JP2008034821A - Semiconductor light-emitting element, and light-emitting apparatus - Google Patents

Semiconductor light-emitting element, and light-emitting apparatus Download PDF

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JP2008034821A
JP2008034821A JP2007163203A JP2007163203A JP2008034821A JP 2008034821 A JP2008034821 A JP 2008034821A JP 2007163203 A JP2007163203 A JP 2007163203A JP 2007163203 A JP2007163203 A JP 2007163203A JP 2008034821 A JP2008034821 A JP 2008034821A
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JP5719496B2 (en
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Takahiko Sakamoto
貴彦 坂本
Masahiko Onishi
雅彦 大西
Yoshiki Inoue
芳樹 井上
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Nichia Chemical Industries Ltd
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Abstract

<P>PROBLEM TO BE SOLVED: To provide a semiconductor light-emitting element capable of obtaining excellent power efficiency characteristics to achieve the application in the field of illumination apparatuses. <P>SOLUTION: The semiconductor light-emitting element has a light-emitting structure 25 including first conductivity type and second conductivity type semiconductor layers 22, 23; a first conductivity type semiconductor layer 22s exposed from the light-emitting structure; and first and second electrodes 30, 40 each provided on the first conductivity type and second conductivity type layers. A first electrode 30 provided on an exposed surface 22s of the semiconductor layer 22 has at least a first layer 31 and a second layer 32 provided on the first layer, and having a width or an area smaller than that of the first layer. The first layer has a light transmissive performance and the second layer has reflection performance for a light of the light-emitting structure. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

本発明は、半導体の発光素子及びそれを用いた発光装置に関し、特に発光素子の電極構造に関する。   The present invention relates to a semiconductor light emitting element and a light emitting device using the same, and more particularly to an electrode structure of the light emitting element.

窒化物半導体を用いた発光素子は、そのワイドバンドギャップ特性から、近紫外から赤色域で発光が得られるため、種々の研究が成されている。窒化物半導体発光素子の一般的な基本構造は、基板上に、n型窒化物半導体、活性層、p型窒化物半導体を積層した構造で、p型層、一部露出されたn型層に各電極が設けられた構造となり、電極構造を含む発光素子構造について研究されている。特に、その高出力化を目指して、様々な発光素子構造、並びに電極構造が提案されている。   Various studies have been made on light-emitting elements using nitride semiconductors because light emission can be obtained in the near ultraviolet to red region due to their wide band gap characteristics. A general basic structure of a nitride semiconductor light-emitting device is a structure in which an n-type nitride semiconductor, an active layer, and a p-type nitride semiconductor are stacked on a substrate. A p-type layer and a partially exposed n-type layer are formed on the substrate. A structure in which each electrode is provided has been studied, and a light-emitting element structure including an electrode structure has been studied. In particular, various light emitting element structures and electrode structures have been proposed with the aim of increasing the output.

特開2003−060236号公報Japanese Patent Laid-Open No. 2003-060236 特開2005−229085号公報JP 2005-229085 A 特開2003−133590号公報JP 2003-133590 A 特開2004−179347号公報JP 2004-179347 A 特開2005−317931号公報JP 2005-317931 A 特開2001−102631号公報JP 2001-102631 A 特開2004−128321号公報JP 2004-128321 A 特開2002−016282号公報JP 2002-016282 A 特開2002−221529号公報JP 2002-221529 A 特開平9−232632号公報 段落51〜63 図7〜9Japanese Patent Laid-Open No. 9-232632 Paragraphs 51 to 63 FIGS. 7 to 9

従来の提案として、n型層に設けられるn電極について、ITOなどの透明電極を用いること(特許文献1,2)、2層構造として、上層に金属層・反射層を一部(特許文献3,10)、全部(特許文献4,5)、重ねて設ける構造がある。
別の提案として、活性層からの発光に対して、n電極の高さを低くして遮光効果を抑えること(特許文献6)、n電極の側面を傾斜させて反射効果を高めること(特許文献7)などがある。また、発光構造内に凹凸構造を設けて、光取り出し効率を高めることも提案されている(特許文献8,9)。
As a conventional proposal, for the n electrode provided in the n-type layer, a transparent electrode such as ITO is used (Patent Documents 1 and 2), and a metal layer / reflective layer is partially formed on the upper layer as a two-layer structure (Patent Document 3). , 10), all (Patent Documents 4 and 5), there is a structure in which they are stacked.
As another proposal, for light emission from the active layer, the height of the n electrode is reduced to suppress the light shielding effect (Patent Document 6), and the reflection effect is enhanced by tilting the side surface of the n electrode (Patent Document 6). 7). It has also been proposed to increase the light extraction efficiency by providing an uneven structure in the light emitting structure (Patent Documents 8 and 9).

しかしながら、前者の提案では、n電極に透明導電膜を用いる際に、電流広がり・均一性、ひいては素子の高抵抗化・電圧値(Vf)上昇が問題なり、後者の提案では、電極材料による光の吸収・損失、形状のバラツキ・量産性が問題となる。また、電力効率(lm/W)の向上は、発光素子、特に窒化物半導体の発光素子において、照明分野など、高出力用途において重要な要求事項となるが、これらの問題は電力効率を低下させ、このような分野、用途への応用の妨げとなる。   However, in the former proposal, when a transparent conductive film is used for the n-electrode, current spreading / uniformity, and consequently, the resistance of the element and the voltage value (Vf) increase are problematic. Absorption and loss, shape variation and mass productivity are problems. In addition, improvement of power efficiency (lm / W) is an important requirement for high-power applications such as lighting fields in light-emitting elements, particularly nitride semiconductor light-emitting elements, but these problems reduce power efficiency. This hinders application in such fields and applications.

本発明の課題は、発光構造に隣接して設けられる電極に透光性電極を用いて、素子の低抵抗化、高出力化、高電力効率化(lm/W)、高い量産性・低コスト化、の少なくともいずれか、好ましくはその多くを実現する発光素子、及び発光装置を提供することにある。   It is an object of the present invention to use a translucent electrode as an electrode provided adjacent to a light emitting structure, to reduce the resistance, increase the output, increase the power efficiency (lm / W) of the element, and achieve high mass productivity and low cost. An object of the present invention is to provide a light-emitting element and a light-emitting device that realize at least one of, or many of them.

本発明の第1の態様に係る発光素子は、第1,2導電型の半導体層を含む発光構造と、発光構造から露出された第1導電型の半導体層と、第1,2導電型層に各々設けられた第1,2電極と、を有し、第1導電型半導体層の露出表面に設けられた第1電極が、第1層と、第1層上に第1層より幅の狭い若しくは面積の小さい第2層と、を少なくとも有し、発光構造の光に対して、第1層が透光性を、第2層が反射性を有する。幅広・大面積の第1層において、第1導電型層との接触面積を大きくして素子抵抗、Vfを低下させ、幅狭,小面積の第2層において、電極内、ひいては素子構造の電流広がりを改善し、電極抵抗、ひいては素子抵抗を下げて、発光構造からの発光を反射性の第2層で吸収・損失する問題を低減させる。   A light emitting device according to a first aspect of the present invention includes a light emitting structure including first and second conductive type semiconductor layers, a first conductive type semiconductor layer exposed from the light emitting structure, and first and second conductive type layers. And the first electrode provided on the exposed surface of the first conductivity type semiconductor layer is wider than the first layer on the first layer and the first layer. And a second layer having a small or small area. The first layer has a light-transmitting property and the second layer has a reflecting property with respect to light having a light-emitting structure. In the first layer of wide and large area, the contact area with the first conductivity type layer is increased to lower the element resistance and Vf, and in the second layer of narrow and small area, the current in the electrode and thus the element structure The spread is improved, the electrode resistance, and hence the element resistance is lowered, and the problem of absorbing and losing light emitted from the light emitting structure in the reflective second layer is reduced.

上記第1の態様における他の形態としては、第1層が、少なくとも隣接する発光構造の方向に、第2層から突出した突出部を有する、ことで、並設された発光構造への電流注入が好適になされ、第1層が透光性で第2層が発光構造から十分に離間されることで、好適な光取り出しが実現される。   In another form of the first aspect, the first layer has a protrusion protruding from the second layer at least in the direction of the adjacent light emitting structure, so that current is injected into the light emitting structures arranged in parallel. And the first layer is translucent and the second layer is sufficiently separated from the light emitting structure, so that suitable light extraction is realized.

本発明の第2の態様に係る発光素子は、第1,2導電型の半導体層を含む発光構造と、該発光構造から露出された第1導電型の半導体層と、該第1,2導電型層に各々設けられた第1,2電極と、を有し、第1導電型半導体層の露出表面に設けられた第1電極が、第1層と、第1層上に第1層より幅の狭い若しくは面積の小さい第2層と、を少なくとも有し、第1層が透光性を、第2層が反射性を有すると共に、電極形成面内において、発光構造間に第1電極が設けられ、第1電極が、隣接する発光構造側面と第1,2層端部との距離が、第1層より第2層が長くなるように設けられている。幅広,大面積の下層側(第1層)が第1電極を挟む発光構造に近接して配置され、幅狭,小面積の上層側(第2層)が該電極を挟む発光構造から離間されて配置されることで、第1電極の抵抗値を低減させ、第1導電型層との接触面積増、隣接する発光構造への電流注入を良好として、光取り出し向上・光吸収・損失低減、させることができる。   A light emitting device according to a second aspect of the present invention includes a light emitting structure including first and second conductivity type semiconductor layers, a first conductivity type semiconductor layer exposed from the light emitting structure, and the first and second conductivity types. A first electrode provided on the exposed surface of the first conductivity type semiconductor layer from the first layer on the first layer and the first layer. A second layer having a small width or a small area, the first layer having translucency, the second layer having reflectivity, and the first electrode between the light emitting structures within the electrode formation surface. The first electrode is provided such that the distance between the side surface of the adjacent light emitting structure and the end portions of the first and second layers is longer in the second layer than in the first layer. A wide, large area lower layer side (first layer) is disposed close to the light emitting structure sandwiching the first electrode, and a narrow, small area upper layer side (second layer) is spaced from the light emitting structure sandwiching the electrode. To reduce the resistance value of the first electrode, increase the contact area with the first conductivity type layer, improve the current injection into the adjacent light emitting structure, improve light extraction, reduce light absorption, reduce loss, Can be made.

上記第1,2の態様に係る他の形態としては、(1)第2層の突出部が、第1層の外周の略全域に設けられている、(2)発光構造と第1電極との間に、該発光構造の発光部より高い突起部を有する、(3)突起部が、発光構造から分離された半導体構造を有する、(4)突起部が発光構造と分離され、第1層が、突起部の第1電極側の側面に延在し、第2層が突起部から離間している、(5)第1電極の少なくとも一部が、第1導電型露出領域で発光構造内部へ凹んだ凹欠部に配置され、凹欠部が第1電極の外周長の半分以上を囲む、(6)第1電極が外部接続部と、外部接続部から延伸する延伸部と、を有し、外部接続部及び延伸部に、第1,2層がそれぞれ設けられている、などがある。   As other forms according to the first and second aspects, (1) the protruding portion of the second layer is provided in substantially the entire outer periphery of the first layer, (2) the light emitting structure, the first electrode, (3) the protrusion has a semiconductor structure separated from the light emitting structure, (4) the protrusion is separated from the light emitting structure, and the first layer has a protrusion higher than the light emitting part of the light emitting structure. Is extended to the side surface of the protrusion on the first electrode side, and the second layer is separated from the protrusion. (5) At least a part of the first electrode is the first conductivity type exposed region inside the light emitting structure. (6) The first electrode has an external connection portion and an extending portion extending from the external connection portion. In addition, the first and second layers are respectively provided in the external connection portion and the extending portion.

上記1では発光構造から上層側(第2層)への光の到達量を減らし、開口部を大きくして、電極による光吸収・損失を低減し、上記2ではこの光に対する遮蔽効果が好適に得られ、上記3では該遮蔽構造物を量産性に優れた突起構造とでき、上記4では、突起部に延在する第1層により、広範囲に第1電極形成が可能となり、素子抵抗・Vf低減が図れる。 上記6では、発光構造・素子の長尺化、大面積化などで、第1導電型層上に互いに並設して延伸する電極構造と発光構造を有する素子構造において、上記第1電極構造を好適に適用できる。   In 1 above, the amount of light reaching the upper layer side (second layer) from the light emitting structure is reduced, the opening is enlarged, and light absorption / loss by the electrode is reduced. In 2 above, the light shielding effect is suitable. Thus, in 3 above, the shielding structure can be made into a protruding structure with excellent mass productivity, and in 4 above, the first layer can be formed over a wide range by the first layer extending to the protruding portion, and the element resistance / Vf can be formed. Reduction can be achieved. In the above 6, in the element structure having the light emitting structure and the light emitting structure and the electrode structure extending in parallel with each other on the first conductivity type layer by elongating the light emitting structure / element or increasing the area, the first electrode structure is It can be suitably applied.

以上の各態様・形態を発光装置に適用する形態としては、(1)半導体発光素子が、載置部に設けられた発光装置、(2)発光装置が、半導体発光素子を封止する封止部材を有し、該封止部材が、発光素子の光の少なくとも一部を波長変換する光変換部材を有する、ものがある。   The modes and forms described above are applied to a light emitting device as follows: (1) a semiconductor light emitting element is provided on a mounting portion, and (2) the light emitting device is a seal for sealing a semiconductor light emitting element. There is a member having a member, and the sealing member has a light conversion member that converts the wavelength of at least part of light of the light emitting element.

本発明の発光素子では、第1電極の上層側と下層側が、それぞれの光学的特性、光透過性と反射性、を有し、隣接する発光構造と好適な配置、構造となっていることで、光出力、電力効率の向上、素子抵抗、Vfの低減、量産性、など、の効果が得られる。
また、このような発光素子を用いた発光装置では、電気・光特性に優れたものが得られる。
In the light emitting device of the present invention, the upper layer side and the lower layer side of the first electrode have respective optical characteristics, light transmissivity and reflectivity, and have a suitable arrangement and structure with the adjacent light emitting structure. Thus, effects such as light output, improvement of power efficiency, element resistance, reduction of Vf, and mass productivity can be obtained.
In addition, a light-emitting device using such a light-emitting element can be obtained with excellent electrical and optical characteristics.

以下、発明の実施の形態について適宜図面を参照して説明する。ただし、以下に説明する発光素子・装置は、本発明の技術思想を具体化するためのものであって、本発明を以下のものに特定しない。特に、以下に記載されている構成部品の寸法、材質、形状、その相対的配置等は特定的な記載がない限りは、本発明の範囲をそれのみに限定する趣旨ではなく、単なる説明例にすぎない。なお、各図面が示す部材の大きさや位置関係等は、説明を明確にするため誇張していることがある。さらに、本発明を構成する各要素は、複数の要素を同一の部材で構成して一の部材で複数の要素を兼用する態様としてもよいし、逆に一の部材の機能を複数の部材で分担して実現することもできる。   Hereinafter, embodiments of the invention will be described with reference to the drawings as appropriate. However, the light-emitting element / device described below is for embodying the technical idea of the present invention, and the present invention is not limited to the following. In particular, the dimensions, materials, shapes, relative arrangements, and the like of the components described below are not intended to limit the scope of the present invention only to specific examples unless otherwise specified. Only. Note that the size, positional relationship, and the like of the members shown in each drawing may be exaggerated for clarity of explanation. Furthermore, each element constituting the present invention may be configured such that a plurality of elements are constituted by the same member and the plurality of elements are shared by one member, and conversely, the function of one member is constituted by a plurality of members. It can also be realized by sharing.

(実施の形態1)
図1を参照して、実施の形態1に係るLED100の具体例の構成について説明する。ここで、図1Aは、実施の形態1に係るLEDを電極配置面側からみた平面を、図1Bは、図1AのA−A線における断面を説明する概略図である。
図1の発光素子の構造は、基板10上に、バッファ層などの下地層21を介して、第1導電型層のn型窒化物半導体層22、発光部となる活性層23、第2導電型層のp型窒化物半導体層24が積層された積層構造からなる半導体構造20を有し、n型層22の一部が露出されてn電極(第1電極)30が設けられ、第1,2導電型層(とその間の活性層)が設けられた発光構造25の表面25tであるp型層24s上にp電極(第2電極)40が設けられた素子構造を有している。
(Embodiment 1)
With reference to FIG. 1, the structure of the specific example of LED100 which concerns on Embodiment 1 is demonstrated. Here, FIG. 1A is a schematic diagram illustrating a plane of the LED according to Embodiment 1 as viewed from the electrode arrangement surface side, and FIG. 1B is a schematic diagram illustrating a cross section taken along line AA of FIG. 1A.
1 has a structure in which an n-type nitride semiconductor layer 22 serving as a first conductivity type, an active layer 23 serving as a light emitting portion, a second conductivity are provided on a substrate 10 via an underlayer 21 such as a buffer layer. A p-type nitride semiconductor layer 24 having a laminated structure in which a p-type nitride semiconductor layer 24 is laminated, a part of the n-type layer 22 is exposed, and an n-electrode (first electrode) 30 is provided. , A device structure in which a p-electrode (second electrode) 40 is provided on a p-type layer 24s which is a surface 25t of the light-emitting structure 25 provided with two conductivity type layers (and an active layer therebetween).

更に図1に係る具体例では、第1電極30は、矩形状の素子構造26、発光構造25において、その角部付近に発光構造を内側に凹ませるように第1導電型露出領域22sが設けられた凹欠部22aの電極形成領域22eに設けられ、円形状の電極の外周長さの半分以上を囲むような内壁面25sを備える発光構造25が並設されている。更に、発光構造と第1電極30との間に複数の突起部60が、発光構造よりも長く電極の外周長を囲むように設けられている。すなわち、n電極が、円弧状に発光構造に湾入した凹欠部22aに設けられ、その外縁を突起部60がその電極の外周長の半分以上、ここでは約257°の円弧状、で、更にその外側の外縁を、突起部領域より開口する外周長さの長い、開口幅・角度の大きな発光構造25(側面25s)が電極30の外周長の半分以上、ここでは約235°の円弧状、でそれぞれ囲むように並設されている。   Further, in the specific example according to FIG. 1, the first electrode 30 is provided with a first conductivity type exposed region 22s in the rectangular element structure 26 and the light emitting structure 25 so that the light emitting structure is recessed inward in the vicinity of the corner. A light emitting structure 25 having an inner wall surface 25s that is provided in the electrode forming region 22e of the recessed portion 22a and that surrounds more than half of the outer peripheral length of the circular electrode is arranged in parallel. Further, a plurality of protrusions 60 are provided between the light emitting structure and the first electrode 30 so as to surround the outer peripheral length of the electrode longer than the light emitting structure. That is, the n-electrode is provided in the concave portion 22a that is inserted into the light emitting structure in an arc shape, and the outer edge of the n-electrode is a half or more of the outer peripheral length of the electrode, here an arc shape of about 257 °, Further, the outer edge of the light emitting structure 25 (side surface 25s) having a long outer peripheral length opening from the protrusion region and having a large opening width and angle is more than half of the outer peripheral length of the electrode 30, in this case, an arc shape of about 235 °. , Are arranged side by side so as to surround each.

また、第1電極30は、下層側に設けられた透光性の透明導電膜の第1層31と、その上の上層側に、反射性の金属膜の第2層32が積層された構造で、第2電極40は、発光構造の上25tのほぼ全面に設けられた透光性の透明導電膜の電極41と、その上に設けられたパッド電極42を有する構造となっている。図1に係る具体例では、n側電極30及びp側電極40の下層側・オーミック電極と、上層側・外部接続電極と、しては、同一構造として、それぞれ、ITOと、Rh/Pt/Auをこの順に積層した膜と、で構成する。上層側は、多層膜で構成されるこの例では、最下層、すなわち透光性の下層との界面側、に、反射性の層として、Rhを設け、その上に、バリア層としてのPt層、外部接続層としてのAu層が順に積層された構造となっている。この時、第1電極30の下層側の第1層31が上層側より断面で幅広、平面で大面積に設けられ、上層側の第2層32が断面で幅が狭く、平面で小面積に設けられ、加えて、上層は下層の一部のみに設けられ、上層の外周全周を下層の突出部31pが設けられている。   The first electrode 30 has a structure in which a first layer 31 of a light-transmitting transparent conductive film provided on the lower layer side and a second layer 32 of a reflective metal film are laminated on the upper layer side thereon. Thus, the second electrode 40 has a structure having an electrode 41 of a translucent transparent conductive film provided on almost the entire surface of the light emitting structure 25t and a pad electrode 42 provided thereon. In the specific example of FIG. 1, the lower layer side / ohmic electrode and the upper layer side / external connection electrode of the n-side electrode 30 and the p-side electrode 40 have the same structure, respectively, ITO, Rh / Pt / And a film in which Au is laminated in this order. In this example, in which the upper layer is formed of a multilayer film, Rh is provided as a reflective layer on the lowermost layer, that is, the interface side with the translucent lower layer, and a Pt layer as a barrier layer is provided thereon. In this structure, an Au layer as an external connection layer is laminated in order. At this time, the first layer 31 on the lower layer side of the first electrode 30 is wider in cross section than the upper layer side and provided in a large area on the plane, and the second layer 32 on the upper layer side is narrow in cross section and has a small area on the plane. In addition, the upper layer is provided only in a part of the lower layer, and the lower layer protrusion 31p is provided on the entire outer periphery of the upper layer.

このように、下層側、特に第1導電型層22のオーミック電極、が幅広、大面積であることで、第1導電型層22との接触面積・幅を大きくでき、接触抵抗、ひいては素子抵抗、素子100の駆動電圧Vfを低減させることができる。他方、そのような幅広、大面積の下層が、透光性を有することで、第1電極下の半導体層を伝播し、その伝播層と電極との界面における電極による、若しくは隣接する発光構造側面25sから出射して電極に到達する、光の吸収・損失を低減でき、光出力、ひいては素子の電力効率を向上させることができる。   As described above, since the lower layer side, in particular, the ohmic electrode of the first conductivity type layer 22 is wide and large in area, the contact area / width with the first conductivity type layer 22 can be increased, and the contact resistance, and hence the element resistance. The drive voltage Vf of the element 100 can be reduced. On the other hand, such a wide, large-area lower layer has translucency so that it propagates through the semiconductor layer under the first electrode, and the side surface of the light emitting structure is adjacent to or adjacent to the electrode at the interface between the propagation layer and the electrode. It is possible to reduce the absorption and loss of light emitted from 25 s and reaching the electrode, and to improve the light output and, in turn, the power efficiency of the element.

また、上層及び下層の発光構造側の端部と第1電極30に隣接する発光構造側面25sとの距離が、下層側より上層側が長いことで、発光構造からの出射光が第2層に到達する量を低減でき、特に図1に示すように、第2層は第1層に比して厚膜、第1層高さが発光構造の発光部(活性層)より低い場合に好ましい。これは、図3Aに示すように電極30と発光構造25間が光学的に広く開口した開口部28が設けられた構造となり、第1導電型層内伝播する光を好適に取り出し可能となる。また、第2層32に到達する光が多くなるような厚膜の第2層若しくは発光部下方となる高さの第1層である場合に、側面25sからの出射光への遮光作用が大きくなり、上記第1電極構造で、その量を低減する効果が顕著となるため、このような電極構造とすることが好ましい。更に、第1電極に並設される発光構造部が、第1電極の外周を囲む領域が大きくなると、電極形成領域、すなわち上記凹欠部内で発光構造側面25sからの出射光が領域内に閉じ込められる傾向にあるため、上述したような電極構造であることで、それを回避でき好ましい。   In addition, since the distance between the end of the upper and lower layers on the light emitting structure side and the light emitting structure side surface 25s adjacent to the first electrode 30 is longer on the upper layer side than the lower layer side, the emitted light from the light emitting structure reaches the second layer. In particular, as shown in FIG. 1, the second layer is preferable when the second layer is thicker than the first layer and the height of the first layer is lower than the light emitting portion (active layer) of the light emitting structure. As shown in FIG. 3A, this has a structure in which an opening 28 having an optically wide opening between the electrode 30 and the light emitting structure 25 is provided, and light propagating in the first conductivity type layer can be suitably extracted. Further, when the second layer 32 is a thick layer that increases the amount of light reaching the second layer 32 or the first layer is located below the light emitting portion, the light shielding effect on the emitted light from the side surface 25s is large. Thus, since the effect of reducing the amount becomes remarkable in the first electrode structure, it is preferable to use such an electrode structure. Furthermore, when the area surrounding the outer periphery of the first electrode of the light emitting structure arranged in parallel with the first electrode becomes larger, the emitted light from the side surface 25s of the light emitting structure is confined in the area in the electrode forming area, that is, the recessed portion. Therefore, the electrode structure as described above is preferable because it can be avoided.

また、このような光閉じ込め効果の高い発光構造形状を備えた発光素子では、発光構造と第1電極との間に、光学的機能を備えた構造物の突起部があると、上述した出射光が第2層に到達する量を低減でき、すなわち、突起部による光学的な機能、例えば反射・散乱機能、により閉じ込め効果を低減でき、好ましい。
以下、本実施形態及び本発明における各構成に詳述するが、本実施形態に限らず、他の実施形態への適用、並びに、各構成を適宜組み合わせる応用も可能である。
Further, in the light emitting device having such a light emitting structure shape having a high light confinement effect, if there is a protruding portion of a structure having an optical function between the light emitting structure and the first electrode, the above-described emission light Is preferable because the confinement effect can be reduced by the optical function of the protrusion, for example, the reflection / scattering function.
Hereinafter, although it explains in full detail in each structure in this embodiment and this invention, the application not only to this embodiment but to other embodiment and the application which combines each structure suitably are also possible.

〔半導体構造・素子構造・発光構造〕
発光素子構造は、図1などに示すように、基板上に半導体構造20、特に各層が積層された積層構造が設けられてなるが、基板を除去するなど、基板の無い、加えて下記下地層など素子能動領域外の層の無い構造、基板中に導電型領域を設けるなどして基板を含む素子領域・構造とすることもできる。発光構造25は、図1の例では、第1,2導電型層22, 24とその間の活性層23が設けられた構造として示すように、半導体構造20による発光領域が設けられた構造となり、更に同一面側に第1,2電極30, 40を設ける電極構造である。この電極構造では、基板面内の素子領域内に第1電極30若しくは第1導電型層露出領域22sと、発光構造25の領域とが少なくとも配置された構造となる。発光構造25としては、このような活性層若しくは発光層を第1,2導電型層の間に設ける構造が好ましいが、その他にp−n接合部を発光部とする構造、p−i−n構造、mis構造、などの発光構造とすることもできる。また、素子構造中、若しくは各導電型層中に、一部半絶縁・絶縁性、i型層、逆導電型の層・領域が設けられていても良く、例えば電流注入域を制御する半絶縁・絶縁性,i型層などで形成される電流阻止層・領域、電極との接合用の逆導電型で形成される逆トンネル層などが設けられた構造でも良い。
[Semiconductor structure / element structure / light emitting structure]
As shown in FIG. 1 and the like, the light-emitting element structure is provided with a semiconductor structure 20 on a substrate, particularly a laminated structure in which each layer is laminated. It is also possible to provide a device region / structure including a substrate by providing a structure having no layer outside the device active region, or providing a conductive type region in the substrate. In the example of FIG. 1, the light emitting structure 25 has a structure in which a light emitting region by the semiconductor structure 20 is provided, as shown as a structure in which the first and second conductivity type layers 22 and 24 and the active layer 23 therebetween are provided. Further, the first and second electrodes 30 and 40 are provided on the same surface side. This electrode structure has a structure in which at least the first electrode 30 or the first conductivity type layer exposed region 22s and the region of the light emitting structure 25 are arranged in the element region in the substrate surface. The light emitting structure 25 is preferably a structure in which such an active layer or a light emitting layer is provided between the first and second conductivity type layers. In addition, a structure having a pn junction as a light emitting part, p-i-n A light emitting structure such as a structure, a mis structure, or the like can also be used. Further, a semi-insulating / insulating, i-type layer, or a reverse-conducting type layer / region may be provided in the element structure or in each conductive type layer, for example, semi-insulating to control a current injection region. A structure provided with a current blocking layer / region formed of an insulating, i-type layer or the like, a reverse tunnel layer formed of a reverse conductivity type for bonding with an electrode, or the like may be used.

発光構造25となる半導体、例えば図1具体例の窒化物半導体は、基板の上に、MOVPE等の成長方法により形成される。窒化物半導体の成長基板としては、サファイア(C面、A面、R面)、スピネル(MgAl)、SiC、NGO(NdGaO)基板、LiAlO基板、LiGaO基板、若しくはSi基板、GaN等の半導体基板、等が挙げられ、成長方法としては本実施形態で用いるMOVPE(有機金属気相成長法)、MOCVD(有機金属化学気相成長法)の他に、HVPE(ハイドライド気相成長法)、MBE(分子線エピタキシー法)等が挙げられる。好ましくは、基板としては、窒化物半導体と異なる材料の異種基板、更に好ましくは透光性基板、であることで、上記第1,2電極が同一面に形成された素子構造で、光取り出しに優れたものとできるためであり、具体例としては、サファイア基板、スピネル基板がある。光透過性の乏しい基板、例えば半導体基板、金属基板などは、基板と半導体との間に光反射層を設ける構造とすることもできる。また、窒化ガリウム系化合物半導体材料としては、一般式InAlGa1−x−yN(0≦x≦1、0≦y≦1、0≦x+y≦1)のものを、特に後述のようにその二元・三元混晶を好適に用いることができ、また、これに加えてIII族元素としてB、V族元素としてNの一部をP、Asで置換されたものを用いてもよい。また各導電型の窒化物半導体としては、n型窒化物半導体はn型不純物として、Si,Ge,Sn,S、O,Ti,Zr,CdなどのIV族元素又はVI族元素等のいずれか1つ以上、好ましくはSi,Geを添加し、p型窒化物半導体層はp型不純物としてMg,Zn,Be,Mn,Ca,Sr等を含有している。また、窒化物半導体以外に、GaAs、GaP系化合物半導体、AlGaAs、InAlGaP、系化合物半導体などの他の半導体材料にも適用することができる。 A semiconductor to be the light emitting structure 25, for example, the nitride semiconductor in the specific example of FIG. 1 is formed on a substrate by a growth method such as MOVPE. As a growth substrate of the nitride semiconductor, sapphire (C-plane, A-plane, R-plane), spinel (MgAl 2 O 4 ), SiC, NGO (NdGaO 3 ) substrate, LiAlO 2 substrate, LiGaO 3 substrate, or Si substrate, Examples of the growth method include MOVPE (metal organic chemical vapor deposition) and MOCVD (metal organic chemical vapor deposition) used in this embodiment, and HVPE (hydride vapor deposition). Method), MBE (molecular beam epitaxy method) and the like. Preferably, the substrate is a heterogeneous substrate made of a material different from that of a nitride semiconductor, more preferably a translucent substrate, so that the element structure in which the first and second electrodes are formed on the same surface is used for light extraction. This is because it can be made excellent, and specific examples include a sapphire substrate and a spinel substrate. A substrate with poor light transmittance, such as a semiconductor substrate or a metal substrate, may have a structure in which a light reflecting layer is provided between the substrate and the semiconductor. In addition, as the gallium nitride-based compound semiconductor material, a material of the general formula In x Al y Ga 1-xy N (0 ≦ x ≦ 1, 0 ≦ y ≦ 1, 0 ≦ x + y ≦ 1) is used. The binary and ternary mixed crystals can be preferably used as described above, and in addition to this, B is used as a group III element and N is partially substituted with P and As as a group V element. Also good. Further, as each type of nitride semiconductor, the n-type nitride semiconductor is an n-type impurity, and is any one of group IV elements such as Si, Ge, Sn, S, O, Ti, Zr, Cd, or group VI elements. One or more, preferably Si and Ge are added, and the p-type nitride semiconductor layer contains Mg, Zn, Be, Mn, Ca, Sr, etc. as p-type impurities. In addition to nitride semiconductors, the present invention can also be applied to other semiconductor materials such as GaAs, GaP compound semiconductors, AlGaAs, InAlGaP, and compound compound semiconductors.

〔発光素子の具体例・製造例〕
本実施形態の図1の発光素子の具体的な半導体構造、積層構造20としては、基板10上に、下地層21として、膜厚20nmのGaNのバッファ層と、膜厚1μmのアンドープGaN層、を
その上の第1導電型層22(n型層)として、膜厚5μmのSi(4.5×1018/cm)ドープGaNのn側コンタクト層と、コンタクト層と活性層との間の領域に、0.3μmのアンドープGaN層と、0.03μmのSi(4.5×1018/cm)ドープGaN層と、5nmのアンドープGaN層と、4nmのアンドープGaN層と2nmのアンドープIn0.1Ga0.9N層とを繰り返し交互に10層ずつ積層された多層膜、を
n型層の上の活性層23として、膜厚25nmのアンドープGaNの障壁層と、膜厚3nmのIn0.3Ga0.7Nの井戸層とを繰り返し交互に6層ずつ積層し、最後に障壁層を
積層した多重量子井戸構造、を、
活性層の上の第2導電型層(p型層)として、4nmのMg(5×1019/cm)ドープのAl0.15Ga0.85N層と2.5nmのMg(5×1019/cm)ドープIn0.03Ga0.97N層とを繰り返し5層ずつ交互に積層し、最後に上記AlGaN層を積層したp側多層膜層と、膜厚0.12μmのMg(1×1020/cm)ドープGaNのp側コンタクト層、を、
積層した構造(発光波長465nm,青色LED)を用いることができる。これらの層は、例えば、C面サファイア基板上にMOVPEでc軸成長した窒化物半導体結晶で形成することができる。
[Specific examples and production examples of light-emitting elements]
As the specific semiconductor structure and laminated structure 20 of the light emitting device of FIG. 1 of the present embodiment, a GaN buffer layer having a thickness of 20 nm and an undoped GaN layer having a thickness of 1 μm are formed as a base layer 21 on a substrate 10. As a first conductivity type layer 22 (n-type layer) thereon, a 5 μm-thick Si (4.5 × 10 18 / cm 3 ) -doped GaN n-side contact layer, and between the contact layer and the active layer In the region of 0.3 μm undoped GaN layer, 0.03 μm Si (4.5 × 10 18 / cm 3 ) doped GaN layer, 5 nm undoped GaN layer, 4 nm undoped GaN layer, and 2 nm undoped. A multilayer film in which 10 layers of In 0.1 Ga 0.9 N layers are alternately and repeatedly stacked is used as an active layer 23 on the n-type layer, and a 25 nm thick undoped GaN barrier layer and 3 nm thick film are formed. of in 0.3 Ga 0. Laminated by six layers alternately repeating the well layer of N, finally multiple quantum well structure formed by laminating a barrier layer, a
As the second conductivity type layer (p-type layer) on the active layer, a 4 nm Mg (5 × 10 19 / cm 3 ) -doped Al 0.15 Ga 0.85 N layer and a 2.5 nm Mg (5 × 10 19 / cm 3 ) Doped In 0.03 Ga 0.97 N layers are alternately stacked 5 layers at a time, and finally the p-side multilayer film layered with the AlGaN layer and Mg film with a thickness of 0.12 μm. A p-side contact layer of (1 × 10 20 / cm 3 ) doped GaN,
A stacked structure (emission wavelength 465 nm, blue LED) can be used. These layers can be formed of, for example, a nitride semiconductor crystal grown c-axis by MOVPE on a C-plane sapphire substrate.

第1導電型層露出(領域)22s、発光構造領域25、これらの領域の画定は、積層構造20の一部を所望形状にエッチングなどで、加工・除去することでなされる。具体例としては、上記構造例でp型層側から、フォトリソグラフィーにより所望形状のSiOなどのマスクを設けて、n型コンタクト層の深さ方向一部までを、RIEなどのエッチングで除去して、第1電極形成領域22e(図1の例では凹欠部22a)及び突起部60・その領域、その他露出領域22sを形成する。露出された第1導電型層(n型層中のn側コンタクト層)21sに第1電極30(n電極)の第1層31、第2電極40(p型層側)の透光性のオーミック電極41、として、ITO(約170nm)を形成する。形成方法は、例えば半導体構造上にITO成膜後に、フォトリソグラフィーによりレジストのマスクを形成し、一部をエッチング除去して、各導電型層上に所望形状に形成する、該第1層31、透光性電極41の一部に第2層32・パッド電極42として、Rh(約100nm)/Pt(約200nm)/Au(約500nm)をこの順に積層した構造の膜を設ける。例えばフォトリソグラフィーによりマスク形成後に、上記積層膜を形成して、リフトオフして所望形状に形成する。このように、第1,2電極30, 40を同時に形成、具体的には同一の工程で各電極の各層を形成、することが製造工数低減でき好ましいが、別々の工程、別々の材料、積層構造で形成しても良い。また、この例では、第2電極と同様に、第1電極の第1層31はオーミック部、第2層32は外部接続部33を各々供する電極となる。 The first conductivity type layer exposure (region) 22s, the light emitting structure region 25, and these regions are defined by processing and removing a part of the laminated structure 20 into a desired shape by etching or the like. As a specific example, a mask of SiO 2 or the like having a desired shape is provided by photolithography from the p-type layer side in the above structure example, and a part of the n-type contact layer in the depth direction is removed by etching such as RIE. Thus, the first electrode formation region 22e (the recessed portion 22a in the example of FIG. 1), the protrusion 60 and its region, and the other exposed region 22s are formed. The exposed first conductive type layer (n-side contact layer in the n-type layer) 21s has a light-transmitting property of the first layer 31 of the first electrode 30 (n-electrode) and the second electrode 40 (p-type layer side). As the ohmic electrode 41, ITO (about 170 nm) is formed. For example, after forming the ITO film on the semiconductor structure, a resist mask is formed by photolithography, and a part of the resist structure is removed by etching to form a desired shape on each conductive type layer. A film having a structure in which Rh (about 100 nm) / Pt (about 200 nm) / Au (about 500 nm) is laminated in this order is provided as a second layer 32 and a pad electrode 42 on a part of the translucent electrode 41. For example, after forming a mask by photolithography, the laminated film is formed and lifted off to form a desired shape. Thus, it is preferable to form the first and second electrodes 30, 40 simultaneously, specifically, to form each layer of each electrode in the same process, which can reduce the number of manufacturing steps, but separate processes, separate materials, and lamination You may form with a structure. In this example, similarly to the second electrode, the first layer 31 of the first electrode serves as an ohmic portion, and the second layer 32 serves as an electrode for providing an external connection portion 33.

図1の例では点線で示すように、各電極の外部接続部33, 43を露出させて、その他の領域を被覆する保護膜50、例えばSiO、を設ける。また、図1の例では、更に、素子領域26の外縁を、基板が露出までエッチングで除去した基板露出領域10sを設けている。この露出領域10sは基板(ウエハ)分割の割溝として機能させることができ、好ましいが、特に設けなくても良い。最後に、この例では□320μm(320μm角)に基板10を分割して、LEDチップを得る。尚、この例では、LEDチップの基板露出幅約5μm、周縁部のn型層露出幅約15μmで、分割前のウエハではその2倍幅あるほぼ中央部を分割
位置としてLEDチップを得る。
In the example of FIG. 1, as shown by the dotted lines, the external connection portions 33 and 43 of the respective electrodes are exposed, and a protective film 50 that covers other regions, for example, SiO 2 is provided. Further, in the example of FIG. 1, a substrate exposed region 10s is provided in which the outer edge of the element region 26 is removed by etching until the substrate is exposed. This exposed region 10s can function as a dividing groove for dividing a substrate (wafer) and is preferable, but need not be provided. Finally, in this example, the substrate 10 is divided into □ 320 μm (320 μm square) to obtain an LED chip. In this example, the LED chip is obtained with the substrate exposed width of the LED chip being about 5 μm and the n-type layer exposed width of the peripheral portion being about 15 μm.

以上の例で示す各構造の寸法としては、基板10の厚さとしては50〜200μm程度(上記例では約90μm)、積層構造20では下地層21の厚さは1〜2μm程度、n型半導体層22の厚さは1〜2μm程度、活性層・発光層23の厚さは50〜150nm程度、p型半導体層24の厚さは、100〜300nm程度、n型露出層22s表面から発光構造の高さは1〜3μm(上記例では約1.5μm)程度、第1層(第1電極)・第2電極(下層)の厚さは0.01〜0.5μm程度、第2層・パッド電極の厚さは0.3〜1.5μm程度、外部接続部・パッド電極の幅・径は50〜150μm程度である。また、上記例では、第1層31は、第2層32の外周全域で突出部31pが約5μmで設けられ、突起部60は幅・径が約2μm、間隔約1μmで設けられている。   As the dimensions of the structures shown in the above examples, the thickness of the substrate 10 is about 50 to 200 μm (in the above example, about 90 μm), and in the laminated structure 20, the thickness of the base layer 21 is about 1 to 2 μm. The layer 22 has a thickness of about 1 to 2 μm, the active layer / light emitting layer 23 has a thickness of about 50 to 150 nm, the p-type semiconductor layer 24 has a thickness of about 100 to 300 nm, and the light emitting structure from the surface of the n-type exposed layer 22s. Is about 1 to 3 μm (about 1.5 μm in the above example), and the thickness of the first layer (first electrode) and the second electrode (lower layer) is about 0.01 to 0.5 μm. The thickness of the pad electrode is about 0.3 to 1.5 μm, and the width / diameter of the external connection portion / pad electrode is about 50 to 150 μm. Further, in the above example, the first layer 31 is provided with the protruding portion 31p with a width of about 2 μm and an interval of about 1 μm at the entire outer periphery of the second layer 32.

〔電極・電極構造〕
発光素子100の電極は、上記例で示すように、発光構造上25tに設けられる第2電極40と、発光構造25から離間した第1導電型層22s上に設けられる第1電極30を有する。このように、基板10の同一面側、すなわち、半導体構造上に、各導電型の電極が設けられることが好ましいが、半導体構造、それに加えて基板を挟んで対向する面上に各々電極が設けられる構造でも良い。また、基板10は、上記例の半導体層の成長基板に限らず、成長基板を研磨、LLO(Laser Lift Off)などで除去する形態、その成長基板が除去された半導体構造が別の担体となる部材、基板に設けられる形態でもよく、その際に担体部材と半導体構造間に他の層、例えば、導電性膜、光反射性膜、などが設けられる構造をとることもできる。上記発光素子の例では、半導体構造上の同一面側に第1,2電極が設けられ、該面側を主発光側とする構造となっている。
[Electrode / electrode structure]
As shown in the above example, the electrode of the light emitting element 100 includes a second electrode 40 provided on the light emitting structure 25t and a first electrode 30 provided on the first conductivity type layer 22s spaced from the light emitting structure 25. As described above, it is preferable that each conductivity type electrode is provided on the same surface side of the substrate 10, that is, on the semiconductor structure. However, in addition to the semiconductor structure, each electrode is provided on the opposite surface across the substrate. The structure can be used. Further, the substrate 10 is not limited to the growth substrate of the semiconductor layer in the above example, and the growth substrate is removed by polishing, LLO (Laser Lift Off) or the like, and the semiconductor structure from which the growth substrate is removed serves as another carrier. It may be in the form of being provided on a member or a substrate, and in that case, a structure in which another layer such as a conductive film or a light reflecting film is provided between the carrier member and the semiconductor structure may be adopted. In the example of the light emitting element, the first and second electrodes are provided on the same surface side on the semiconductor structure, and the surface side is the main light emitting side.

従って、発光構造25上の第2電極40の下層側は、オーミック接触用として、また、上記図1の例のように上層側よりも幅広、大面積で形成される場合は、電流拡散導体として機能し、発光構造から光取り出しを良好とするため、透光性材料、光透過性の構造、例えば遮光性部材で多孔質状、格子状の構造など、を用いることができ、好ましくは透光性材料でほぼ全面を覆う導電膜で形成する。他方、第1電極30の下層側の第1層31は、主にオーミック接触用として機能する。これは、第1導電型半導体上に、露出領域22sと発光構造25が平面内に配置された構造では、上記拡散体としての下層側電極41と異なり、面内への電流拡散導体は、発光構造下方の第1導電型半導体領域が主にそれを担う構造となり、後述の実施形態で示す、第1電極30の配線部は、これを補完する機能をなす。従って、上記担持基板を用いる場合、その基板導電性若しくは基板と発光構造間の導電膜、特に透光性導電膜により、第1導電型側の拡散導体とすることもできる。   Accordingly, the lower layer side of the second electrode 40 on the light emitting structure 25 is used for ohmic contact, and as a current spreading conductor when formed in a wider and larger area than the upper layer side as in the example of FIG. In order to function and improve light extraction from the light-emitting structure, a light-transmitting material, a light-transmitting structure, such as a porous structure or a lattice-like structure with a light-shielding member, etc. can be used. It is formed of a conductive film covering almost the entire surface with a conductive material. On the other hand, the first layer 31 on the lower layer side of the first electrode 30 mainly functions for ohmic contact. This is because, in the structure in which the exposed region 22s and the light emitting structure 25 are arranged in a plane on the first conductivity type semiconductor, the current diffusion conductor into the surface emits light, unlike the lower layer side electrode 41 as the diffuser. The first conductive type semiconductor region below the structure mainly takes charge of the structure, and the wiring portion of the first electrode 30 shown in an embodiment described later has a function of complementing this. Therefore, in the case of using the carrier substrate, the diffusion conductor on the first conductivity type side can be formed by the substrate conductivity or the conductive film between the substrate and the light emitting structure, particularly the translucent conductive film.

発光素子100内の発光構造25は、図1,2に示すように1つの発光構造の一部、例えば図1のように角部若しくは隅部、図2のように長手方向の一方の端部、図8のように該一方端部と側面一部に、第1電極形成領域22eとして、発光構造内へ湾入するような凹欠部22aとして設けられても良く、図3C、4〜6に示すように、大面積の発光構造25、若しくは一部が第1電極形成領域22e・第1導電型層露出領域21sで一部分離されるような構造部25A〜Cを複数有する発光構造25、大面積化した素子構造である場合、若しくは図8のように長尺化した発光構造である場合には、各発光構造部に隣接して第1電極30が設けられる構造であっても良い。このような場合、各電極には、上述したようにその電流拡散を補うものとして、図示するように、第1導電型半導体、発光構造・第2電極下層側、の上に、配線となる延伸部34, 44が設けられる電極構造、互いに分離した複数の電極で構成される電極構造などにより、好ましい電流拡散がなされる。   The light emitting structure 25 in the light emitting element 100 is a part of one light emitting structure as shown in FIGS. 1 and 2, for example, a corner or a corner as shown in FIG. 1, and one end in the longitudinal direction as shown in FIG. As shown in FIG. 8, the first electrode forming region 22e may be provided on the one end and part of the side surface as a recessed portion 22a that enters the light emitting structure. As shown in FIG. 4, a large-area light-emitting structure 25, or a light-emitting structure 25 having a plurality of structure portions 25A to 25C partially separated by a first electrode formation region 22e and a first conductivity type layer exposed region 21s, In the case of an element structure with an increased area or a light emitting structure that is elongated as shown in FIG. 8, a structure in which the first electrode 30 is provided adjacent to each light emitting structure portion may be used. In such a case, as described above, each electrode supplements its current diffusion as described above, and as shown in the drawing, the first conductive type semiconductor, the light emitting structure / second electrode lower layer side, and the extension that becomes the wiring A preferred current diffusion is achieved by the electrode structure provided with the portions 34 and 44, the electrode structure constituted by a plurality of electrodes separated from each other, and the like.

第1電極30の第1層31、第2電極の接触層41は、基板上に第1,2電極が設けられ電極形成側を主発光側とする発光素子構造においては、透光性の膜が形成される。透光性の導電膜、窒化物半導体のp側電極としては、ニッケル(Ni)、白金(Pt)パラジウム(Pd)、ロジウム(Rh)、ルテニウム(Ru)、オスミウム(Os)、イリジウム (Ir)、チタン(Ti)、ジルコニウム(Zr)、ハフニウム(Hf)、バナジウム(V)、ニオブ(Nb)、タンタル(Ta)、コバルト(Co)、鉄 (Fe)、マンガン(Mn)、モリブデン(Mo)、クロム(Cr)、タングステン(W)、ランタン(La)、銅(Cu)、銀(Ag)、イットリウム(Y) よりなる群から選択された少なくとも一種を含む金属、合金、その積層構造、さらには、それらとIn、Sn、Ga、Zn、Cd、Be、Mgなどによる導電性金属化合物、例えば、導電性の酸化物、窒化物などがある。導電性の金属酸化物(酸化物半導体)として、錫をドーピングした厚さ5nm〜10μmの酸化インジウム(Indium Tin Oxide; ITO)、ZnO(酸化亜鉛)、In(酸化インジウム)、またはSnO(酸化スズ)、これらの複合物、例えばIZO(Indium Zinc Oxide)が挙げられ、透光性に有利なことから好適に用いられ、光の波長などにより適宜材料が選択される。また、上記導電性材料のドーピング材料として、半導体の構成元素、半導体のドーパントなどを用いることもできる。 The first layer 31 of the first electrode 30 and the contact layer 41 of the second electrode are light-transmitting films in the light-emitting element structure in which the first and second electrodes are provided on the substrate and the electrode formation side is the main light-emitting side. Is formed. As a light-transmitting conductive film and a p-side electrode of a nitride semiconductor, nickel (Ni), platinum (Pt) palladium (Pd), rhodium (Rh), ruthenium (Ru), osmium (Os), iridium (Ir) , Titanium (Ti), zirconium (Zr), hafnium (Hf), vanadium (V), niobium (Nb), tantalum (Ta), cobalt (Co), iron (Fe), manganese (Mn), molybdenum (Mo) , A metal containing at least one selected from the group consisting of chromium (Cr), tungsten (W), lanthanum (La), copper (Cu), silver (Ag), yttrium (Y), an alloy, a laminated structure thereof, Are conductive metal compounds such as In, Sn, Ga, Zn, Cd, Be, and Mg, for example, conductive oxides and nitrides. As a conductive metal oxide (oxide semiconductor), tin-doped indium oxide (ITO), ZnO (zinc oxide), In 2 O 3 (indium oxide), or SnO with a thickness of 5 nm to 10 μm is doped. 2 (tin oxide), and composites thereof, such as IZO (Indium Zinc Oxide), are preferred because they are advantageous in terms of translucency, and materials are appropriately selected depending on the wavelength of light. Further, a semiconductor constituent element, a semiconductor dopant, or the like can be used as a doping material of the conductive material.

上記具体例で示すように、第1,2電極30, 40の透光性膜(第1層31、下層側)を同一材料・構造とすることが好ましく、更に同一工程で設けることが好ましく、量産性に富む電極構造とできる。同様に、第1,2電極30, 40の上層側に配される金属膜・反射性膜(第2層32、パッド電極、上層)も同一材料・構造、更には同一工程で設けることが好ましい。金属膜、反射性膜としては、上記群から選択される材料(群の一種を含む金属、合金、積層構造)を用いることができる。この第1,2電極の上層側の第2層・パッド電極は、多層膜構造とすることが好ましく、その構造としては、下層側から順に、反射層/パッド部・電流拡散用の金属層の少なくとも2層、好ましくは図3Aに示すように反射層32-1(42-1)/バリア層32-2(42-2)/パッド部用の金属層32-3(42-3)の少なくとも3層を有する構造であることが各層の機能を好適に高めることができ好ましい。反射膜としては、素子の発光に対し光反射率の材料であれば良く、具体的にはAg、Al、Rh等が挙げられ、Rhは安定して好適に用いられ、また透光性膜(第1層、下層側)との接触側に配置される。バリア層はその下層(反射層)・上層(表面層・パッド部)の拡散を防止、保護するようなものであれば良く、具体的な材料としては、W,Moなどの高融点材料や、白金族元素、Ni,Au等、好ましくはPt,W,Mo,Niが好ましい。パッド電極用の材料としてはAu,Alがある。各層の膜厚は、特に限定されないが、0.05〜5μmで形成され、反射層は他の層(それより上層)に比して、薄膜に形成されることが好ましく、その上層のバリア層、パッド層は、反射層より比較的厚膜に形成される。また、上記各層は、単一膜である必要は無く、多層膜で構成されても良く、図3Bに示すように、上記各層間及び第1層との間に保護層、密着層、例えばTi,Niなど、を介在させ、4層(32-1〜32-4,42-1〜42-4)以上で構成しても良い。具体例としては、Rh(反射)/Pt(バリア)/Au(表層)、Al(反射)/Pt(バリア)/Au(表層)、Ti(密着層)/Rh(反射)/Pt(バリア)/Au(表層)、Al(反射)/W(バリア)/Pt(バリア)/Au(表層)、Ni(密着層)/Ag(反射)/Ni(密着・バリア)/Ti(密着層)/Au(表層)をこの順に積層した構造などがある。   As shown in the above specific example, it is preferable that the translucent films (first layer 31, lower layer side) of the first and second electrodes 30, 40 have the same material and structure, and are preferably provided in the same process, An electrode structure with high mass productivity can be obtained. Similarly, the metal film / reflective film (second layer 32, pad electrode, upper layer) disposed on the upper layer side of the first and second electrodes 30, 40 is preferably provided in the same material and structure, and in the same process. . As the metal film and the reflective film, materials selected from the above groups (metals including one kind of group, alloys, laminated structures) can be used. It is preferable that the second layer / pad electrode on the upper layer side of the first and second electrodes has a multilayer film structure. As the structure, in order from the lower layer side, the reflective layer / pad part / current diffusion metal layer At least two layers, preferably at least a reflective layer 32-1 (42-1) / barrier layer 32-2 (42-2) / pad metal layer 32-3 (42-3) as shown in FIG. 3A A structure having three layers is preferable because the function of each layer can be suitably enhanced. The reflection film may be a material having a light reflectance with respect to the light emission of the element, and specifically includes Ag, Al, Rh, etc., and Rh is stably and preferably used, and a light-transmitting film ( The first layer and the lower layer side) are arranged on the contact side. The barrier layer only needs to prevent and protect the diffusion of the lower layer (reflective layer) / upper layer (surface layer / pad portion), and specific materials include high melting point materials such as W and Mo, Platinum group elements, Ni, Au, etc., preferably Pt, W, Mo, Ni are preferred. Examples of the material for the pad electrode include Au and Al. The thickness of each layer is not particularly limited, but it is preferably 0.05 to 5 μm, and the reflective layer is preferably formed as a thin film as compared with other layers (above it), and the upper barrier layer. The pad layer is formed relatively thicker than the reflective layer. Further, each of the layers does not need to be a single film, and may be formed of a multilayer film. As shown in FIG. 3B, a protective layer, an adhesion layer, for example, Ti, is provided between the layers and the first layer. , Ni, etc. may be interposed, and it may be composed of four layers (32-1 to 32-4, 42-1 to 42-4) or more. Specific examples include Rh (reflection) / Pt (barrier) / Au (surface layer), Al (reflection) / Pt (barrier) / Au (surface layer), Ti (adhesion layer) / Rh (reflection) / Pt (barrier). / Au (surface layer), Al (reflection) / W (barrier) / Pt (barrier) / Au (surface layer), Ni (adhesion layer) / Ag (reflection) / Ni (adhesion / barrier) / Ti (adhesion layer) / There is a structure in which Au (surface layer) is laminated in this order.

ここで、第2層・上層は、図1,2,3Aに示すように、製造上、断面が第1層側を幅広とする台形状となる場合があり、このように隣接する発光構造側面25sに対して上方にその発光構造側の側面が傾斜した構造であると、光の反射作用により指向性・軸上光度を高め、発光構造上面25tでの開口幅が広がることができ、好ましい。一方で、断面矩形状(基板に略垂直な側面、逆台形状(上面側が幅広な形状、下方に傾斜した側面)であっても良く、従来知られた製造方法、例えばマスク材料・形状、成膜条件により所望形状とできる。また、第2層・上層が多層膜構造である場合には、図3Bに示すように、単純な多層構造となる場合の他、図3Aに示すように、各層の成膜条件・特性の違いにより、上層側が下層側、特にその側面を覆うように設けられる構造となる形態もある。何れの構造であっても良く、上層側が側面を覆う形態では、第1層(下層)側の反射層が、他の層(バリア層、パッド層)より反射率が高いため、上層の下端面に比して、側面・上面などの反射率が低くなり、本発明の電極構造とすることで、効果的に機能する。このように、上層の下方の反射層は、それより上層の膜より反射率が高く、第2層の上面、側面のほとんどが反射率の低い構造となる。   Here, as shown in FIGS. 1, 2, and 3A, the second layer / upper layer may have a trapezoidal shape in which the cross section is wide on the first layer side, as shown in FIGS. A structure in which the side surface on the light emitting structure side is inclined upward with respect to 25s is preferable because the directivity and the axial luminous intensity can be increased by the light reflecting action, and the opening width on the light emitting structure upper surface 25t can be widened. On the other hand, it may have a rectangular cross section (a side surface substantially perpendicular to the substrate, an inverted trapezoidal shape (a shape with a wide upper surface, a side surface inclined downward), and a conventionally known manufacturing method such as a mask material / shape, If the second layer / upper layer has a multilayer film structure, each layer may have a simple multilayer structure as shown in FIG. Depending on the film formation conditions and characteristics, there is a form in which the upper layer side is provided so as to cover the lower layer side, in particular, the side face thereof. Since the reflective layer on the layer (lower layer) side has a higher reflectance than the other layers (barrier layer, pad layer), the reflectance on the side surface and the upper surface is lower than the lower end surface of the upper layer. The electrode structure works effectively. Picolinimidate, it from high reflectance than the upper layer of the film, the upper surface of the second layer, most of the side surface becomes a low reflectance structure.

第1層は、第2層に比して断面幅広、大面積で形成されることで、第1導電型層との接触面積を大きくして接触抵抗を低減し、素子の駆動電圧Vfも低減させることができる。他方、透光性であることで、第1導電型層の被覆幅・面積が大きくなっても遮光せず、光の吸収・損失を低く抑えて、光取り出し効率向上、高出力化、ひいては発光素子の電力効率を向上させることができる。一方で、第2層から突出した突出部において、電極形成位置より下方の半導体領域で伝播する光を好適に素子外部へ、特に電極形成面側へ取り出すことができ、大面積、幅広の電極による光損失を低減できる。すなわち、図3Aに示すように、隣接する発光構造側面と第2層側面との間が、図中矢印のようにその光伝播領域の出射口(図中白抜き矢印)となる開口部28となるため、第2層と発光構造との距離より長くなる構造が好ましい。特に、第2層が第1層に比して厚膜で設けられる場合、発光構造の発光位置より低い位置まで第1層が設けられ、第2層が発光位置より高い位置まで設けられる場合には、離間距離を長くして、第2層の遮光作用を低減し、開口部28の幅・面積を増大させることが好ましい。   The first layer is formed with a wider cross-section and a larger area than the second layer, so that the contact area with the first conductivity type layer is increased to reduce the contact resistance, and the drive voltage Vf of the element is also reduced. Can be made. On the other hand, because it is translucent, it does not block light even if the coating width and area of the first conductivity type layer is increased, and light absorption and loss are kept low, improving light extraction efficiency, increasing output, and thus emitting light. The power efficiency of the element can be improved. On the other hand, in the protruding portion protruding from the second layer, the light propagating in the semiconductor region below the electrode forming position can be preferably taken out to the outside of the element, particularly to the electrode forming surface side. Light loss can be reduced. That is, as shown in FIG. 3A, an opening 28 between the side surface of the adjacent light emitting structure and the side surface of the second layer becomes an emission port of the light propagation region (open arrow in the figure) as indicated by an arrow in the figure. Therefore, a structure that is longer than the distance between the second layer and the light emitting structure is preferable. In particular, when the second layer is provided thicker than the first layer, the first layer is provided to a position lower than the light emitting position of the light emitting structure, and the second layer is provided to a position higher than the light emitting position. It is preferable to lengthen the separation distance to reduce the light shielding effect of the second layer and increase the width and area of the opening 28.

〔発光構造・電極構造〕
発光構造は、上述したように、発光素子領域中に、図1,2,8に示すように1つである形態、図3C,4〜6に示すように、一部が第1導電型層露出領域22s・第1電極形成領域22eで分離された発光構造部25A〜Cで構成されるものの何れでも良く、素子の面積、特性に応じて適宜選択される。発光構造25と第1電極10は図示するように1対1である必要はなく、第1電極30に挟まれた発光構造のように、2対1など他の関係でもよく、少なくとも発光構造部とそれに並設された第1電極30との組を有する構造であれば良い。
[Light-emitting structure / electrode structure]
As described above, the light emitting structure has one configuration as shown in FIGS. 1, 2, and 8 in the light emitting element region, and a part of the first conductivity type layer as shown in FIGS. 3C and 4 to 6. Any of the light emitting structure portions 25A to 25C separated by the exposed region 22s and the first electrode forming region 22e may be used, and is appropriately selected according to the area and characteristics of the element. The light emitting structure 25 and the first electrode 10 do not have to be one to one as shown in the figure, but may have other relations such as two to one like the light emitting structure sandwiched between the first electrodes 30, and at least the light emitting structure portion. And a structure having a pair of the first electrode 30 arranged in parallel therewith.

基本的な発光素子構造は、各断面図にて観られるように、発光構造25に並設されて第1電極30が設けられた構造部を有するものとなる。このため、このような並設領域では、本発明の電極構造とすることが好ましい。
そのため、第1電極30面積・幅を増加させると、電極端と発光構造部側面との距離が短くなるため、下層側の透光性の第1層が発光構造の近くに配置され、その上の上層側の第2層が遠くに配置された構造とすることが好ましい。特に、各図で示すように、第1電極の外縁として発光構造が設けられる領域では、本発明の電極構造の効果が高まる。
The basic light-emitting element structure has a structure in which the first electrode 30 is provided in parallel with the light-emitting structure 25 as seen in each cross-sectional view. For this reason, the electrode structure of the present invention is preferably used in such a juxtaposed region.
For this reason, when the area and width of the first electrode 30 are increased, the distance between the electrode end and the side surface of the light emitting structure is shortened. Therefore, the light-transmitting first layer on the lower layer side is disposed near the light emitting structure. It is preferable to have a structure in which the second layer on the upper layer side is disposed far away. In particular, as shown in each drawing, the effect of the electrode structure of the present invention is enhanced in the region where the light emitting structure is provided as the outer edge of the first electrode.

第1電極30に対する隣接する発光構造25の領域としては、第1電極30の片側、例えば発光構造に隣接する側若しくは電極外周長の半分、及びそれ以上である場合には、本発明は効果的に機能するため好ましい。特に、一方が素子外部方向若しくは第1電極30の外部接続部・延伸方向に開口し、他方が発光構造25に対向して、閉塞された領域、図1,2の凹欠部、図3C,4〜6の電極延伸部、であるような構造の場合に特に好ましく、更には図4,6に示すように発光構造に内部で囲まれた閉塞領域である場合に更に好ましい。
具体的には、このような領域では、発光構造25の電極側の側面25sの少なくとも一部領域が、互いに対向する内壁を形成するような構造となり、該側面及び第1導電型層露出部から出射する光が閉じ込められ易い構造となっているため、本発明電極構造であることで、光閉じ込め、電極による光吸収・損失が低減できる構造できる。
The present invention is effective when the region of the light emitting structure 25 adjacent to the first electrode 30 is one side of the first electrode 30, for example, the side adjacent to the light emitting structure or half of the electrode outer peripheral length, or more. It is preferable because it functions. In particular, one is open in the element external direction or in the external connection portion / extension direction of the first electrode 30, and the other is opposed to the light emitting structure 25, the closed region, the recessed portion in FIGS. It is particularly preferable in the case of a structure having 4 to 6 electrode extending portions, and more preferably in a closed region surrounded by a light emitting structure as shown in FIGS.
Specifically, in such a region, at least a partial region of the side surface 25s on the electrode side of the light emitting structure 25 has a structure in which inner walls facing each other are formed, from the side surface and the first conductivity type layer exposed portion. Since the emitted light is easily confined, the electrode structure of the present invention can reduce the light confinement and the light absorption / loss caused by the electrode.

第1層31と第2層32とは、図示するように、第1層31上の一部に設けられる構造であること、更に第2層32の全外周に第1層31の突出部31pが設けられる構造であることが好ましい。例えば、第1層と第2層が一部で重なり合い、第2層が第1層の外側へ延在して形成される形態とすることもできる。しかし、上記第1層による開口領域が減少すること、第2層の接着界面が第1層と第1導電型層の複合界面となり密着性が悪くなる場合があること、があり、第1層内に設けられることが好ましい。一方、第2層端部の一部領域が第1層端部とほぼ同一に重なるような形態であっても良い。これは図3Cの点線32Bで示すように、延伸部の幅方向では第1層31に突出部31pが設けられ、延伸方向の端部で重なって形成されるような形態がある。この形態では、外周長の多くを占める延伸方向側面が突出部31pを有するため、全周域が突出部31pを有する場合に比して、僅かに電力効率が低下する程度に抑えることができるため、このような形態でも好適に利用できる。   As shown in the figure, the first layer 31 and the second layer 32 have a structure provided in a part on the first layer 31, and further, the protrusion 31p of the first layer 31 on the entire outer periphery of the second layer 32. Is preferably provided. For example, the first layer and the second layer may partially overlap each other, and the second layer may be formed to extend outside the first layer. However, there are cases where the opening area by the first layer is reduced, the adhesion interface of the second layer becomes a composite interface of the first layer and the first conductivity type layer, and the adhesion may be deteriorated. It is preferable to be provided inside. On the other hand, a form in which a partial region of the end portion of the second layer overlaps with the end portion of the first layer may be substantially the same. As shown by a dotted line 32B in FIG. 3C, there is a form in which the protruding portion 31p is provided in the first layer 31 in the width direction of the extending portion and overlaps at the end portion in the extending direction. In this embodiment, since the side surface in the extending direction that occupies most of the outer peripheral length has the protruding portion 31p, it can be suppressed to the extent that the power efficiency is slightly reduced as compared with the case where the entire peripheral area has the protruding portion 31p. Such a form can also be suitably used.

他方、図3Cの破線32Cで示すように、延伸方向に対して短く設けられる場合、すなわち、延伸方向の幅方向の突出部長さより、延伸方向端部における突出部の長さが大きくなるような場合には、抵抗、特にシート抵抗の大きな第1層により電流拡散を担う領域が多くなり、電流広がりが不十分となる傾向にある。このため、この形態では、幅方向における突出長さを基準として、その2倍幅以下に端部の突出長さとすることで、電流拡散・均一性が好適なものとでき、好ましい。また、図6の例のように、外部接続部33における突出部の突出幅と、延伸部34におけるそれとが異なる形態、すなわち、電極の形状により、特に断面幅・平面の面積、が異なる各電極部で、互いに異なる突出部の幅・長さ、若しくは発光構造と第2層との距離、とする形態でも良い。この場合、大面積・幅広な部分(外部接続部)の方が、突出幅を大きくする方が、電極幅による電流狭窄などが少なく、電極の被覆面積の大きな領域で第1層突出部が幅広に形成されると、好適な開口効果が得られる。他方このように、突出部の幅は、第2層の幅など電極の各部に応じて、変化させることもできる。例えば、図5(電極一部34B-1[32B-1, 31B-1]),図8(延伸部34)の例のように、電極30(延伸部34)の片側、一方側面に発光構造が隣接し、他方に発光構造が設けられず、例えば素子外縁となるような場合には、その幅中心から変位させるなど、図の例では発光構造から遠ざかる方向に第2層を変位、して、発光構造部隣接側の突出部31pの幅・長さ、若しくは第2層と発光構造との距離を、その対向側より、長く・大きくするような形態、とする方が、上述した通り好ましい特性が得られる。特に図5の例では、各電極部(1次延伸部、2次延伸部、外部接続部)で互いに異なる突出部の幅・長さとして、各部に好適な第1,2層を重ね合わせる形態とすることができる。   On the other hand, as shown by the broken line 32C in FIG. 3C, when it is provided short with respect to the stretching direction, that is, when the length of the projecting portion at the end in the stretching direction is larger than the length of the projecting portion in the width direction in the stretching direction. In this case, the first layer having a large resistance, particularly the sheet resistance, has a large area for current diffusion, and the current spread tends to be insufficient. For this reason, in this embodiment, by setting the protruding length of the end portion to a double width or less with respect to the protruding length in the width direction, current diffusion and uniformity can be preferably achieved. In addition, as in the example of FIG. 6, each electrode in which the protruding width of the protruding portion in the external connection portion 33 is different from that in the extending portion 34, that is, the cross-sectional width and the area of the plane are particularly different depending on the electrode shape. It is also possible to adopt a form in which the widths and lengths of the protrusions different from each other, or the distance between the light emitting structure and the second layer are used. In this case, the larger area and the wider portion (external connection portion) have less protrusion of current due to the electrode width when the protrusion width is increased, and the first layer protrusion portion is wider in the region where the electrode coverage is large. If it is formed, a suitable opening effect can be obtained. On the other hand, the width of the protruding portion can be changed according to each part of the electrode such as the width of the second layer. For example, as in the example of FIG. 5 (electrode part 34B-1 [32B-1, 31B-1]) and FIG. 8 (extension part 34), the light emitting structure is formed on one side and one side of the electrode 30 (extension part 34). In the example shown in the figure, the second layer is displaced in the direction away from the light emitting structure, for example, when the light emitting structure is not provided on the other side and is located at the outer edge of the element. As described above, it is preferable that the width and length of the protruding portion 31p on the side adjacent to the light emitting structure or the distance between the second layer and the light emitting structure be longer and larger than the opposite side. Characteristics are obtained. In particular, in the example of FIG. 5, the first and second layers suitable for each part are overlapped as the width and length of the protrusions different from each other in each electrode part (primary extension part, secondary extension part, external connection part). It can be.

次に、図3Dの断面概略図を用いて、下層及びその両側の突出部の各作用について詳述する。図中の矢印に示すように、発光構造部25からその外側に延在した露出部の電極形成領域22eを有する第1導電型層22に、光が基板10などに反射されて伝搬する。この時に、上層32領域32cに到達する光が、下層31が介在することで、屈折、反射されるなどの光制御作用により、上層32に到達する光が低減され、すなわち、上層による光吸収が防がれ、上層領域32c外側に方向転換された光が取り出されることにより上層の光反射、半導体層への再入光を防止することができる。これにより、光損失低減、光取り出し効率向上ができ、他方下層による幅広、大面積の電極により電流拡散、均一化に寄与して、素子の電力効率が向上する。   Next, each action of the lower layer and the protrusions on both sides thereof will be described in detail using the schematic cross-sectional view of FIG. 3D. As indicated by the arrows in the figure, light is reflected by the substrate 10 or the like and propagates to the first conductivity type layer 22 having the exposed electrode forming region 22e extending from the light emitting structure 25 to the outside. At this time, the light reaching the upper layer 32 region 32c is intervened by the lower layer 31, so that the light reaching the upper layer 32 is reduced by the light control action such as refraction and reflection, that is, the light absorption by the upper layer is reduced. The light that is prevented and redirected to the outside of the upper layer region 32c is taken out, so that the light reflection of the upper layer and the re-entry light to the semiconductor layer can be prevented. As a result, the light loss can be reduced and the light extraction efficiency can be improved. On the other hand, the wide and large area electrode by the lower layer contributes to current diffusion and uniformity, and the power efficiency of the element is improved.

このような効果は、発光構造部上の第2電極よりも、そこから外側に延在する第1導電型半導体層の第1電極で高くできる。また、上層32(その領域32c)から発光構造部25側に突出した突出部31aよりも、その対向側32e、好適には電極に隣接する発光構造部25から開口している側、更には素子外周側で高くできる。後者の具体的な構造は、第1電極と発光構造部を切断する断面において、上層から両側に突出した突出部において、一方が発光構造部側で、他方がその対向側に配置される構造を有する。前者の効果向上は、発光構造部25上の第2電極では、下層の面積、その占有率が大きく、上層がそれに比して小さいため、上層42における遮光、光損失効果が低く、また、発光層23から種々の方向の光が上層に到達するため、その光を制御することが困難になるためである。他方、第1電極では、図に示すように、発光層23からの光の内、その電極形成領域の第1導電型半導体層に伝搬する光は、電極形成の露出面22eに対して高角度な成分が多くを占めるため、図中矢印に示すような下層による光制御作用を好適に発揮することができる。
また、後者における突出部の発光構造部側32aとその対向側32eの対比では、発光構造部側突出部32aから取り出された光は、上述したように、上層32が隣接する発光構造部から離間されて、光取り出し窓が大きくなる効果がある一方で、隣接する発光構造部への再入光、上層による光反射・吸収があるため、その突出部から取り出された光が、最終的に素子外部に取り出される割合が小さくなる。他方、その対向側では、そのような問題が低減されるため、下層による光制御、突出部による光取り出しが効果的に機能する。特に、その対向側32eが、電極30が隣接する発光構造部から開口された領域であると、その機能が高まり好ましく、更には、それが素子外周側であると、直接的に素子外部に取り出されるため最も好ましい。
Such an effect can be enhanced by the first electrode of the first conductivity type semiconductor layer extending outward from the second electrode on the light emitting structure portion. Further, rather than the protruding portion 31a protruding from the upper layer 32 (the region 32c) to the light emitting structure portion 25 side, the opposite side 32e, preferably the side opened from the light emitting structure portion 25 adjacent to the electrode, and further the element It can be increased on the outer peripheral side. A specific structure of the latter is a structure in which, in a cross section cutting the first electrode and the light emitting structure portion, one is disposed on the light emitting structure portion side and the other is disposed on the opposite side of the protruding portion protruding from the upper layer to both sides. Have. The improvement in the former effect is that, in the second electrode on the light emitting structure 25, the area and the occupation ratio of the lower layer are large, and the upper layer is smaller than that, so that the light shielding and light loss effects in the upper layer 42 are low. This is because light in various directions from the layer 23 reaches the upper layer, and it becomes difficult to control the light. On the other hand, in the first electrode, as shown in the drawing, the light propagating to the first conductivity type semiconductor layer in the electrode formation region out of the light from the light emitting layer 23 has a high angle with respect to the exposed surface 22e of the electrode formation. Since many components occupy many, the light control action by the lower layer as shown by the arrow in the figure can be suitably exhibited.
In contrast, the light extracted from the light emitting structure side protrusion 32a is separated from the light emitting structure adjacent to the upper layer 32 as described above by comparing the light emitting structure side 32a of the protrusion and the opposite side 32e of the latter. As a result, there is an effect that the light extraction window becomes large, but there is re-entry light to the adjacent light emitting structure part, and light reflection / absorption by the upper layer, so that the light extracted from the protruding part is finally the element The proportion taken out to the outside decreases. On the other hand, since such a problem is reduced on the opposite side, light control by the lower layer and light extraction by the protrusion function effectively. In particular, when the opposing side 32e is a region opened from the light emitting structure part to which the electrode 30 is adjacent, the function is enhanced, and when it is on the outer peripheral side of the element, it is directly taken out from the element. Therefore, it is most preferable.

〔突起部・光学的構造部〕
上記電極30と発光構造25との間に、図1,2,3Bに示すように、突起部60などの光学的な機能、例えば反射,散乱,回折,出射口の機能、を有する構造部を設けることが好ましい。これは、上述したように、発光構造側面25sからの出射光が第2層表面に到達する光量を低減でき、すなわち光損失の原因となる第2層による遮光作用があるためである。このような光学的な構造部としては、第1導電型半導体層露出表面22s上に、透光性の絶縁膜、例えば保護膜50などによる凹凸構造など、光吸収・損失の低い、透光性の材料で形成されることが好ましく、また反射・散乱の機能に限れば金属性の突起部・凹凸部を設けることができる。好ましくは、該電極・発光構造間領域が狭い領域であるため、付加的な構造物を設けるよりも、半導体の積層構造から分離、具体的には発光構造から分離された半導体構造物により、設けられると精度良く、また高密度に形成でき、光学的機能を高められ、更に発光素子と同様な透光性の材料であるため、好ましい。
[Protrusions / Optical structure]
Between the electrode 30 and the light emitting structure 25, as shown in FIGS. 1, 2, and 3B, a structure portion having an optical function such as a protrusion 60, for example, a function of reflection, scattering, diffraction, and an exit is provided. It is preferable to provide it. As described above, this is because the amount of light emitted from the light emitting structure side surface 25s reaches the surface of the second layer can be reduced, that is, there is a light blocking effect by the second layer that causes light loss. As such an optical structure, a light-transmitting and low-loss light-transmitting property such as a concavo-convex structure made of a light-transmitting insulating film such as a protective film 50 on the exposed surface 22s of the first conductive type semiconductor layer is used. Preferably, it is formed of a material such as that described above, and metallic protrusions and concavo-convex portions can be provided as long as the function of reflection / scattering is limited. Preferably, since the region between the electrode and the light emitting structure is a narrow region, it is separated from the stacked structure of the semiconductor, more specifically, by the semiconductor structure separated from the light emitting structure, rather than providing an additional structure. It is preferable because it can be formed with high accuracy and high density, has an improved optical function, and is a light-transmitting material similar to that of a light-emitting element.

具体的には、図示するように、発光構造25から分離溝25pが設けられて、分離される突起部60として設けることができる。図1,2,8の例(平面視)では発光構造から第1導電型層22上で分離された形状であるが、第1電極側の側面、凹欠部の近傍領域における発光構造に、孔(凹部)を設けて、その孔とそれを囲む発光構造による複合的な構造物とすることもできる。すなわち、図示の例において、突起部と第1導電型層露出部の各領域を反転した形状として形成することもできる。このような突起部若しくは凹部の平面形状としては、図示するような円形状が、高密度な配置、量産性に富み最も好ましいが、楕円形状、四角・矩形状、多角形状、それらの複合的な形状であっても良い。また、その配置は、これら形状に応じて、四角・矩形状,平行四辺形状,三角形状,六角形状(蜂の巣状)、などが適宜選択され、高密度な配置がなされる。これら構造物(突起・凹・溝の各部)の平面の大きさとしては、幅0.5〜5μm、好ましくは1〜3μmであると、好適に製造できる。また、断面形状は、上記第2層と同様に、台形・逆台形状、矩形状などの形状とでき、透光性部材で構成されると、光学的機能が反射だけに限らないため、側面の傾斜による反射への依存性が第2層よりも低くできるが、好ましくは第2層同様に、底面側が幅広な、上面側が電極方向に傾斜した、形状である。このように、突起部とは、光学的な機能を有する構造物であり、その表面・上面62・側面63, 64、若しくは他の材料との界面などにより、光学的な機能を供することができるものであれば良い。ここで、図3は、本発明の発光素子の一部構造について説明する断面図(図3A、図3B)、平面図(図3C)である。   Specifically, as shown in the figure, a separation groove 25p is provided from the light emitting structure 25, and can be provided as a protrusion 60 to be separated. In the example of FIGS. 1, 2, and 8 (plan view), the shape is separated from the light emitting structure on the first conductivity type layer 22, but the light emitting structure in the side surface on the first electrode side, in the vicinity of the recessed portion, It is also possible to provide a complex structure by providing a hole (concave portion) and a light emitting structure surrounding the hole. That is, in the illustrated example, each region of the protruding portion and the first conductive type layer exposed portion can be formed in an inverted shape. As the planar shape of such protrusions or recesses, a circular shape as shown in the drawing is most preferable because of its high density arrangement and mass productivity, but an elliptical shape, a square / rectangular shape, a polygonal shape, or a combination thereof. It may be a shape. In addition, the arrangement is appropriately selected from a square / rectangular shape, a parallelogram shape, a triangular shape, a hexagonal shape (honeycomb shape), and the like, and a high-density arrangement is made. As the plane size of these structures (protrusions / concaves / grooves), a width of 0.5 to 5 μm, preferably 1 to 3 μm, can be suitably manufactured. Further, the cross-sectional shape can be a trapezoidal shape, an inverted trapezoidal shape, a rectangular shape, etc., similar to the second layer, and when configured with a translucent member, the optical function is not limited to reflection. Although the dependence on reflection due to the inclination of the second layer can be made lower than that of the second layer, it is preferable that the bottom surface side is wide and the upper surface side is inclined in the electrode direction, like the second layer. As described above, the protrusion is a structure having an optical function, and can provide an optical function by the surface, the upper surface 62, the side surfaces 63 and 64, or an interface with another material. Anything is fine. Here, FIG. 3 is a cross-sectional view (FIGS. 3A and 3B) and a plan view (FIG. 3C) for explaining a partial structure of the light-emitting element of the present invention.

また、図3に示すように、このような光学的機能の構造物は、第1導電型層露出領域と同様に、発光構造と異なる非発光領域を構成し、上記透光性材料であると、図3A,Bに示すように、その形成領域は開口部28として機能できる。この時、構造部・突起部60が、発光構造から電気的に分離されている(図1,2,8の例)と、図3Bに示すように、第1電極が突起部形成領域にまで、延在して形成する(延在部31p-1)こともできる。好ましくは、図示するように、透光性の第1層が延在して形成し、第2層を離間させることで、発光構造側面からの出射光に対して、図中白抜き矢印で示すように、好適な光散乱作用が働き、第2層の光吸収・損失を低減できる。また、第1層の接触面積増加によるVf低減も可能となる。突起部に延在する第1層は、図に示すように、電極側の側面63、更には上面62に到達する形状とすることができる。   Further, as shown in FIG. 3, such a structure having an optical function constitutes a non-light-emitting region different from the light-emitting structure, like the first conductive type layer exposed region, and is the light-transmitting material. 3A and 3B, the formation region can function as the opening 28. At this time, when the structure portion / projection portion 60 is electrically separated from the light emitting structure (examples of FIGS. 1, 2, and 8), as shown in FIG. 3B, the first electrode reaches the protrusion formation region. Further, it can be formed to extend (extending portion 31p-1). Preferably, as shown in the figure, the light-transmitting first layer is formed to extend, and the second layer is separated so that the emitted light from the side surface of the light emitting structure is indicated by a white arrow in the figure. Thus, a suitable light scattering action works, and the light absorption / loss of the second layer can be reduced. Further, Vf can be reduced by increasing the contact area of the first layer. As shown in the drawing, the first layer extending to the protruding portion can be shaped to reach the side surface 63 on the electrode side and further to the upper surface 62.

〔保護膜50〕
図1,2,3Aなどに示すように、各電極の外部接続部33, 43を開口させた開口部51w, 52wを設けて、他の素子領域のほぼ全面を覆う保護膜が形成されていても良い。保護膜は、素子構造側を主光取り出し側とする際には、透光性材料で形成される。また、開口部の形状は、図1,2に示すように、電極上面の一部が開口される形状であっても良く、図3Aに示すように電極の下層側(透光性膜)を覆い、開口部内に、保護膜端部から離間して電極の上層側が設けられる形態でも良く、比較的薄膜で形成される下層側の透光性を覆う形態であることが好ましい。保護膜材料としては、従来知られたもの、例えば、珪素の酸化物・窒化物、アルミニウムの酸化物など、発光素子の光・波長に応じて、適宜透光性の良い材料を用いると良い。膜厚としては、0.1〜3μm程度、好ましくは、0.2〜0.6μm程度で形成される。
[Protective film 50]
As shown in FIGS. 1, 2, 3A, etc., openings 51w, 52w are formed by opening the external connection portions 33, 43 of the respective electrodes, and a protective film covering almost the entire surface of the other element regions is formed. Also good. The protective film is formed of a translucent material when the element structure side is the main light extraction side. The shape of the opening may be a shape in which a part of the upper surface of the electrode is opened as shown in FIGS. 1 and 2, and the lower layer side (translucent film) of the electrode as shown in FIG. 3A. The upper layer side of the electrode may be provided in the opening portion so as to be separated from the end portion of the protective film, and the lower layer side translucency formed by a relatively thin film is preferably covered. As the protective film material, a material having a high light-transmitting property may be used as appropriate depending on the light and wavelength of the light-emitting element, such as a conventionally known material, for example, silicon oxide / nitride, aluminum oxide, or the like. The film thickness is about 0.1 to 3 μm, preferably about 0.2 to 0.6 μm.

また、素子領域外周域の保護膜端部は、図1に示すように、基板露出部10s(溝)と略同一に形成されても良く、図2示すように、該露出部10sから離間して、素子領域26の第1導電型層露出部22s上から素子内部を被覆するような形態でも良い。前者は、基板露出10sの半導体除去と同じ工程で、保護膜も除去することで、半導体構造領域と略同一形状の保護膜が形成される。他方、図2の例では、素子領域外周を画定するようにその近傍域の保護膜50を除去して、第1導電型層22sを露出させ、その保護膜露出部内で、半導体層を除去して、基板露出部10sを設ける。基板分割、LEDチップ形成は、該基板露出部がある例では、その溝部を割り溝としても用いる。素子領域外縁部は、このように基板露出部とすること、すなわち素子領域を半導体構造領域として設けても良く、他の図4〜6の例で示すように、発光構造外縁の第1導電型層露出領域でも良く、その他に、発光構造端部を外縁部とするもの、これらの複合的な外縁を形成するものでも良い。   Further, as shown in FIG. 1, the end portion of the protective film in the outer peripheral area of the element region may be formed substantially the same as the substrate exposed portion 10s (groove), and is separated from the exposed portion 10s as shown in FIG. Thus, the inside of the element may be covered from above the first conductivity type layer exposed portion 22s of the element region 26. In the former, a protective film having substantially the same shape as the semiconductor structure region is formed by removing the protective film in the same process as the semiconductor removal of the substrate exposure 10s. On the other hand, in the example of FIG. 2, the protective film 50 in the vicinity thereof is removed so as to define the outer periphery of the element region, the first conductivity type layer 22s is exposed, and the semiconductor layer is removed in the exposed portion of the protective film. Then, a substrate exposed portion 10s is provided. In the example where the substrate is exposed and the LED chip is formed, the groove portion is also used as a split groove in an example where the substrate exposed portion is present. The element region outer edge portion may be a substrate exposed portion as described above, that is, the element region may be provided as a semiconductor structure region. As shown in other examples of FIGS. The layer exposure region may be used, or a light emitting structure end portion as an outer edge portion or a composite outer edge thereof may be used.

(比較例)
上記実施形態1の具体例(図1)において、その第2層と同一幅・面積で第1層を設ける例、その第2層より小さい、例えば第2層外周から1μmほど内側が外周となる、第1層を設ける例、と比較すると、上記実施形態1の具体例の方が、順方向電圧が低く、光出力が同程度若しくは僅かに向上する傾向が観られる。このことから、上記具体例の第1層と同等な大きさの第2層を設けると、順方向電圧はほぼ同等であるが、光出力が急激に低下するものとなると考えられる。このため、大電流注入の高出力域、大面積の発光素子では顕著に差が現れると考えられ、特に電力効率を低下させる要因になると考えられる。
また、上記具体例では、100lm/W超の発光素子及び発光装置(図7Bに示す樹脂封止型のもの)が実現できるが、この比較例ではそれより低下し、100未満となるものがある。
(Comparative example)
In the specific example of the first embodiment (FIG. 1), an example in which the first layer is provided with the same width and area as the second layer, which is smaller than the second layer, for example, 1 μm inside from the outer periphery of the second layer is the outer periphery. Compared with the example in which the first layer is provided, the specific example of the first embodiment has a tendency that the forward voltage is lower and the optical output is improved to the same degree or slightly. From this, it is considered that when the second layer having the same size as the first layer of the above specific example is provided, the forward voltage is substantially the same, but the light output is rapidly decreased. For this reason, it is considered that a significant difference appears in a light-emitting element having a high output area and a large area for large current injection, and in particular, is considered to be a factor for reducing power efficiency.
Further, in the above specific example, a light emitting element and a light emitting device (resin-sealed type shown in FIG. 7B) exceeding 100 lm / W can be realized, but in this comparative example, there are those that are lower than that and less than 100. .

(実施形態2)
実施形態2としては、上記実施形態1の具体例(図1)のLED形状が略正方形であるのに比して、図2に示すように、LEDの大きさを420μm×240μmとして、長方形状にする形態である。実施形態1と同様に、半導体構造を形成し、発光素子構造・突起部・電極形成領域を形成し、各電極を設け、基板露出、基板分割により形成できる。ここで、図2Aは、この発光素子の平面図の概略を、図2Bは2AのAA切断面における断面図の概略を示すものである。
(Embodiment 2)
In the second embodiment, the LED shape is 420 μm × 240 μm in a rectangular shape as shown in FIG. 2 compared to the square shape of the specific example (FIG. 1) of the first embodiment. It is a form to make. As in the first embodiment, a semiconductor structure is formed, a light emitting element structure, a protrusion, and an electrode formation region are formed, each electrode is provided, and the substrate can be formed by exposing the substrate and dividing the substrate. Here, FIG. 2A shows an outline of a plan view of the light-emitting element, and FIG. 2B shows an outline of a cross-sectional view taken along the line AA of 2A.

第1電極30の形成領域22eである発光構造25の凹欠部22aは、発光構造の隅部として、長手形状の発光素子の領域・発光構造に対して、長手方向の一方の端部側に設けられ、該長手方向を開口して、その他を囲むような外縁が発光構造で形成され、具体的には矩形状の電極形成領域の1辺が開口した外縁形状となっている。そのため、図1の例よりも発光構造、突起部と共に、より大きな割合で電極外周を囲み、具体的には第1電極周囲の約8割の外周長を発光構造が囲み、突起部は外周全域を囲む形態となっている。このように、第1電極30の外縁が、発光構造25と突起部60とで異なる形状、外周長とすることもでき、突起部・光学的構造部の方が配置の自由度が高いため、外周長を発光構造に比して長くすること、更には、発光構造部の開口部に突起部を設けることができる。また、発光構造25が一部開口した電極形成領域22eであることで、光の閉じ込めが弱まり、光出力に寄与するため好ましく、他方、光学的構造部が開口部を塞ぎ、外周全域に設けられても、非発光部であるため、光出力・取り出し効率低減作用は小さく抑えられる。従って、この例では、光特性に優れた発光素子が得られる。   The recessed portion 22a of the light emitting structure 25, which is the formation region 22e of the first electrode 30, is located on one end side in the longitudinal direction as a corner of the light emitting structure with respect to the region / light emitting structure of the long light emitting element. The outer edge is provided with a light emitting structure that opens in the longitudinal direction and surrounds the others, and specifically has an outer edge shape in which one side of a rectangular electrode forming region is opened. Therefore, the outer periphery of the electrode is surrounded at a larger rate together with the light emitting structure and the protrusion than in the example of FIG. 1, specifically, the light emitting structure surrounds the outer peripheral length of about 80% around the first electrode. It is the form which surrounds. In this way, the outer edge of the first electrode 30 can have a different shape and outer peripheral length between the light emitting structure 25 and the protrusion 60, and the protrusion / optical structure has a higher degree of freedom in arrangement. The outer peripheral length can be made longer than that of the light emitting structure, and further, a protrusion can be provided at the opening of the light emitting structure. Further, it is preferable that the light emitting structure 25 is an electrode forming region 22e with a partly opened, so that light confinement is weakened and contributes to the light output.On the other hand, the optical structure part closes the opening and is provided in the entire outer periphery. However, since it is a non-light emitting portion, the light output / extraction efficiency reduction effect can be kept small. Therefore, in this example, a light emitting element having excellent optical characteristics can be obtained.

〔変形例〕
上記図2の変形例としては、図8に示すような、より細長い発光素子とすることもできる。外形寸法は550μm×150μmで、長手形状の発光構造に対して、長手方向端部に外部接続部33を含む電極形成領域22eが設けられている。図1,2の例とは異なり、この電極形成領域22eは、電極を囲むような凹欠部とならずに一部発光構造が、長手方向で電極の側面一部に延在して設けられた形状となっている。さらに第1電極、第2電極は、それぞれ基点となる長手方向両端付近の外部接続部33,43から長手方向に延伸する延伸部34,44を有しており、互いの延伸部は発光構造を挟むように幅方向に対向して、並進するように設けられる。第1電極の延伸部は発光構造に隣接して設けられ、長手方向で第2電極の基点から離間する位置まで設けられ、第2電極延伸部も同様に第1電極の基点から離間する位置まで設けられている。尚、第1電極延伸部34が設けられている領域は、発光構造の幅が、他の領域、例えば外部接続部44との間の領域など延伸部34端部から長手方向外側の領域、の幅よりも狭く形成され、内側に凹んだ構造となっている。このように延伸部により、発光構造の長手方向への電流広がりを良好なものとできる。
[Modification]
As a modification of FIG. 2 described above, a longer and lighter light emitting element as shown in FIG. 8 may be used. The external dimensions are 550 μm × 150 μm, and an electrode forming region 22e including the external connection portion 33 is provided at the end in the longitudinal direction with respect to the light emitting structure having a long shape. Unlike the example of FIGS. 1 and 2, this electrode forming region 22e is not provided with a recessed portion surrounding the electrode, but a part of the light emitting structure is provided extending in a part of the side surface of the electrode in the longitudinal direction. It has a different shape. Furthermore, each of the first electrode and the second electrode has extending portions 34 and 44 extending in the longitudinal direction from the external connection portions 33 and 43 in the vicinity of both ends in the longitudinal direction, which are the base points, and each extending portion has a light emitting structure. Opposing in the width direction so as to sandwich, it is provided to translate. The extending portion of the first electrode is provided adjacent to the light emitting structure, and is provided to a position away from the base point of the second electrode in the longitudinal direction, and the second electrode extending portion is similarly provided to a position away from the base point of the first electrode. Is provided. The region where the first electrode extending portion 34 is provided has a width of the light-emitting structure of another region, for example, a region outside the longitudinal direction from the end of the extending portion 34 such as a region between the external connecting portion 44 and the like. It is formed narrower than the width and has a concave structure inside. As described above, the extension portion can improve the current spread in the longitudinal direction of the light emitting structure.

この例では、図示するように、電極領域における第1層31の突出幅、すなわち、第2層32端部と第1層31端部との距離、が略同一で形成されている。このように、延伸部に応じて第2層も設けられると、発光構造、特にこの変形例のように幅が狭い長手形状の発光構造25、に対して、好適な電流広がりを実現できる。他方、発光構造の外部側面の一部を覆うように第1電極が設けられ、特に長手方向の側面に並設される延伸部34, 44が設けられると、発光構造25からの光を遮る作用が働くが、図示するように、幅の狭い・小面積で第2層が設けられることで、この作用を抑えることができる。更に、発光構造側の突出部をその反対側より幅広として発光構造から第2層をより離間させることで、効果を高めることができる。上述したように、延伸部34を有するような電極構造である場合に、外部接続部33に第2層32を設け、延伸部34に第2層を設けない形態、すなわち第1層より第2層の延伸長さを短くする形態、であると、電流広がりが低下、電圧上昇傾向にあるが、低電流域での使用では第1層31の延伸部が設けられているため、光取り出しに優れたものとできる。すなわち、第1,2層を有する外部接続部と、そこから延伸する第1層の延伸部で構成されることで、低電流域に優れた発光素子が得られる。   In this example, as shown in the figure, the protruding width of the first layer 31 in the electrode region, that is, the distance between the end of the second layer 32 and the end of the first layer 31 is formed to be substantially the same. Thus, when the second layer is also provided in accordance with the extending portion, it is possible to realize a suitable current spread for the light emitting structure, particularly the light emitting structure 25 having a narrow longitudinal shape as in this modification. On the other hand, when the first electrode is provided so as to cover a part of the outer side surface of the light emitting structure, and particularly when the extending portions 34 and 44 provided side by side in the longitudinal direction are provided, the light from the light emitting structure 25 is blocked. However, as shown in the figure, this action can be suppressed by providing the second layer with a small width and a small area. Further, the effect can be enhanced by making the protrusion on the light emitting structure side wider than the opposite side to further separate the second layer from the light emitting structure. As described above, when the electrode structure has the extending portion 34, the external connection portion 33 is provided with the second layer 32 and the extending portion 34 is not provided with the second layer, that is, the second layer is more than the first layer. If the extension length of the layer is shortened, the current spread decreases and the voltage tends to increase, but when used in a low current region, the extension portion of the first layer 31 is provided, so that light extraction is possible. It can be excellent. That is, a light emitting device excellent in a low current region can be obtained by being constituted by the external connection portion having the first and second layers and the extending portion of the first layer extending therefrom.

また、図2の例とは異なり、突起部60が、第1電極30と発光構造部25との間の領域に加えて、発光構造及び第1電極の外周部、すなわち、素子領域の外縁部の外周ほぼ全域に、突起部が設けられており、このような形態では、発光構造側面からの出射光を、基板面の法線方向に好適な指向性を持たせることができる。   Further, unlike the example of FIG. 2, in addition to the region between the first electrode 30 and the light emitting structure 25, the protrusion 60 has an outer peripheral portion of the light emitting structure and the first electrode, that is, an outer edge of the element region. Protrusions are provided in almost the entire outer periphery of the light-emitting element, and in such a form, the emitted light from the side surface of the light emitting structure can have a suitable directivity in the normal direction of the substrate surface.

この変形例について、本発明を検討するため、図8の例1と、その比較例として、下層31が無い例2、上層31の延伸部34が無く(下層31の延伸部が有り)、図中点線部33rで示す外部接続部だけの第2層とする例3について検討する。各例の発光素子は、φ5mmの砲弾型の発光装置(青色)に搭載して評価すると、下表1の特性のものが得られる。ここで、半導体層、電極構造、各部の寸法は、上記実施形態1の具体例(□320μm)と同様である。   In order to study the present invention with respect to this modification, Example 1 in FIG. 8 and Comparative Example 2 in which there is no lower layer 31, there is no extension part 34 in the upper layer 31 (there is an extension part in the lower layer 31), Consider Example 3 in which only the external connection portion indicated by the middle dotted line portion 33r is the second layer. When the light emitting element of each example is mounted on a bullet-type light emitting device (blue) with a diameter of 5 mm and evaluated, the light emitting elements having the characteristics shown in Table 1 below are obtained. Here, the semiconductor layer, the electrode structure, and the dimensions of each part are the same as the specific example (□ 320 μm) of the first embodiment.

Figure 2008034821
上表1から分かるように、例3のように下層だけで延伸部を構成する構造では、Vfが高くなり、また例2のように上層だけで延伸部・第1電極を構成する構造では、延伸部により電極面積、ひいては被覆面積の占有率が大きくなり、すなわち反射性の第2層による遮光効果が高くなることで出力が低下する。
Figure 2008034821
As can be seen from Table 1 above, in the structure in which the extending portion is formed only in the lower layer as in Example 3, Vf is high, and in the structure in which the extending portion and the first electrode are formed only in the upper layer as in Example 2, The stretched portion increases the area of the electrode area and hence the coverage area, that is, the light shielding effect by the reflective second layer is increased, and the output is reduced.

一方、本発明に係る例1では、上層より断面幅広な下層により、上層の電極による遮光、光損失を低減して、上層から突出した下層突出部から光取り出しでき、延伸部によるVf低減、電流拡散・均一化の機能を備えて、その構造による弊害である遮光、光損失を低減して出力を向上させることができ、結果として、電力効率の高い発光素子が得られる。特に、延伸部のように、外部接続部などに比して幅狭な構造であると、図3Dに示すような光の屈折などの制御作用が好適に機能して、延伸部が設けられることによる光損失の増加を抑えることができる。特に図3Dに示すように、発光構造部側の突出部3aよりも、その対向側3e、特に素子外周側における光取り出し効果がより顕著となり、好適に素子外周側、すなわち素子外部へ光を取り出すことができる。   On the other hand, in Example 1 according to the present invention, the lower layer whose cross section is wider than the upper layer can reduce light shielding and light loss by the upper layer electrode, and can extract light from the lower layer protruding portion protruding from the upper layer. With the function of diffusion / uniformization, the output can be improved by reducing the light shielding and light loss, which are harmful effects of the structure, and as a result, a light-emitting element with high power efficiency can be obtained. In particular, when the structure is narrower than the external connection part, such as the extension part, the control action such as light refraction as shown in FIG. 3D preferably functions and the extension part is provided. The increase in optical loss due to can be suppressed. In particular, as shown in FIG. 3D, the light extraction effect on the opposite side 3e, particularly on the outer peripheral side of the element, becomes more prominent than the protrusion 3a on the light emitting structure side, and light is preferably extracted to the outer peripheral side of the element, that is, outside the element. be able to.

また、この例で示すように、発光構造の側面構成辺、特に素子外形構成辺の1辺において、その発光構造、素子の半分超の長さで延伸部を設ける構造では、その辺における遮光効果、例えば隣接する発光構造の側面発光、電極形成領域22eの露出面からの発光、に対する遮光効果が、大きくなる。これに対し、本発明では、その遮光効果を低減させることができるため、このような延伸部構造に、下層構造が好適に用いられる。特に、この例のように、長手形状の発光素子におけるその長手方向の構成辺でその長さの半分超である場合には、遮光効果がさらに大きくなるため、本発明の遮光効果低減作用が好適に機能する。この時、少なくとも、発光構造側33aに対向する側に突出部を有し、好ましくはその対向側が発光構造部から開口されたような素子外周側であること、さらに好ましくは、両側、すなわち発光構造部側とその対向側(素子外周側)に突出部を有することが好ましい。   In addition, as shown in this example, in the side structure side of the light emitting structure, in particular, one side of the element outer shape side, the light emitting structure, and the structure in which the extending portion is longer than half of the element, the light shielding effect on that side. For example, the light-shielding effect against side light emission of the adjacent light emitting structure and light emission from the exposed surface of the electrode formation region 22e is increased. On the other hand, in this invention, since the light-shielding effect can be reduced, a lower layer structure is used suitably for such an extending | stretching part structure. In particular, as in this example, when the length of the longitudinal light emitting element is more than half of the length in the longitudinal direction, the light shielding effect is further increased. Therefore, the light shielding effect reducing action of the present invention is suitable. To work. At this time, at least the light emitting structure side 33a has a protruding portion on the side facing the light emitting structure side 33a, and preferably the opposite side is the element outer peripheral side opened from the light emitting structure portion, more preferably both sides, that is, the light emitting structure. It is preferable to have protrusions on the part side and the opposite side (element outer peripheral side).

(実施形態3)
図4に示す例では、発光構造25の内部に、電極形成領域22e及び第1電極30が2つ設けられた構造を有し、発光構造部25p間に第1電極が配置された発光構造を有している。従って、長手形状の発光構造部25A〜Bが、その幅方向に第1電極30(形成領域22e)と交互に配置された構造となっており、第1電極30は、幅広な外部接続部33, 43と、そこから長手方向に延伸する幅の狭い延伸部34, 44を有する構造となっている。これにより、長手形状の各発光構造部25A〜Bに対して、並設された第1電極30、主にその延伸部34を有する構造とでき、好適な電流広がり、発光を実現できる構造となっている。ここで、図4Aは、発光素子の平面図の概略であり、図4Bは図4AのAA断面図の概略である。ここでは、発光素子の外形寸法は、□1mm(1mm角)で、各電極の外部接続部など他の構造物の寸法は、素子の大きさに関わる発光構造及びそれに伴う延伸部を除いて、上記例と同様な寸法で形成できる。
(Embodiment 3)
In the example shown in FIG. 4, the light emitting structure 25 has a structure in which two electrode forming regions 22e and two first electrodes 30 are provided, and the light emitting structure in which the first electrode is disposed between the light emitting structure portions 25p. Have. Accordingly, the light emitting structure portions 25A to 25B having a long shape are alternately arranged with the first electrodes 30 (formation regions 22e) in the width direction, and the first electrode 30 has a wide external connection portion 33. , 43 and narrow extending portions 34, 44 extending in the longitudinal direction therefrom. Thereby, it can be set as the structure which has the 1st electrode 30 currently arranged in parallel with respect to each light emitting structure part 25A-B of a longitudinal shape, and the extending part 34 mainly, and becomes a structure which can implement | achieve suitable electric current spreading and light emission. ing. Here, FIG. 4A is a schematic plan view of the light emitting device, and FIG. 4B is a schematic cross sectional view taken along the line AA in FIG. 4A. Here, the external dimensions of the light-emitting element are □ 1 mm (1 mm square), and the dimensions of other structures such as the external connection part of each electrode are excluding the light-emitting structure related to the element size and the extension part accompanying it, It can be formed with the same dimensions as in the above example.

この例では、上述の例(図1,2,8)とは異なり、電極形成領域22eが、外周全域を発光構造に囲まれた構造となっており、また、電極構造も外部接続部33を基点として2方向、この例では発光構造部25A-Bの長手方向両側の2方向、に延伸する延伸部34を有する構造となっている。また、第2電極40(その上層42)も同様に、各発光構造部の長手方向に延伸する延伸部44を、第1電極・その延伸部に、上記交互に配置される発光構造部25A-Bを挟んで対向して配置される。さらに、各発光構造部25A-Bは、その間に、長手方向両端で、幅方向に互いに連結する発光構造部を有し、その環状の発光構造に応じて、第2電40(第2層42)極延伸部も幅方向に延伸して(延伸部43C)、第1電極30を囲むように、四角形の環状の延伸部44が設けられている。ここで、第1,2電極の外部接続部34, 44は、長手方向に、両端の近傍に配置され、互いに対向して各電極の接続部が設けられ、第1電極の接続部は、3つの延伸部34A, 34Bの長手方向端部付近にそれぞれ設けられている。
この構造のように、各電極及びその延伸部若しくは外部接続部、発光構造部が複数設けられる発光素子構造でも本発明は好適に適用される。
In this example, unlike the above-described examples (FIGS. 1, 2, and 8), the electrode forming region 22e has a structure in which the entire outer periphery is surrounded by the light emitting structure, and the electrode structure also includes the external connection portion 33. The base portion has a structure having extending portions 34 extending in two directions, in this example, two directions on both sides in the longitudinal direction of the light emitting structure portions 25A-B. Similarly, in the second electrode 40 (the upper layer 42), the extending portions 44 extending in the longitudinal direction of the respective light emitting structure portions are provided with the light emitting structure portions 25A- Arranged facing each other across B. Further, each light emitting structure 25A-B has a light emitting structure connected to each other in the width direction at both ends in the longitudinal direction, and according to the annular light emitting structure, the second electric 40 (second layer 42). ) The pole extending portion is also extended in the width direction (extending portion 43C), and a rectangular annular extending portion 44 is provided so as to surround the first electrode 30. Here, the external connection portions 34, 44 of the first and second electrodes are arranged in the vicinity of both ends in the longitudinal direction, and the connection portions of the respective electrodes are provided to face each other, and the connection portions of the first electrode are 3 The two extending portions 34A and 34B are provided near the ends in the longitudinal direction.
As in this structure, the present invention is also suitably applied to a light emitting element structure in which each electrode and its extended portion or external connection portion and a plurality of light emitting structure portions are provided.

(実施形態4)
実施形態4としては、図6に示すように、実施形態3の図4の例に比して、電極形成領域22e及び発光構造、構造部は、同様な形態である一方で、第2電極40の上層42延伸部44が、第1電極30の外部接続部34側の端部で開口した形状となっている。第1電極30で挟まれた内側構造部25Aでは、外側構造部25Bの外部接続部44から幅方向に延伸する1次延伸部42A-1と、そこから長手方向に延伸する2次延伸部42A-2が設けられている。また、第1電極30の構造、形成領域22eも異なる形態となっており、発光構造部25A, Bの長手方向の端部に外部接続部34が配置され、それを基点として、第2電極40の外部接続部44側へ一方向に延伸する延伸部44Bを備えた構造となっている。また、第2電極40の外部接続部44は、第1電極30と交互に配置された長手形状の発光構造部25A, Bに対して、1対1の関係でなく、外側の発光構造部25Bにそれぞれ設けられている。ここで、図6Aは、発光素子の平面図の概略である。また、この例の発光素子の寸法は、素子外形が□800μm(800μm角)であり、その他の構造物の寸法は、素子の大きさに関わる発光構造及びそれに伴う延伸部を除いて、上記例とほぼ同様である。
(Embodiment 4)
In the fourth embodiment, as shown in FIG. 6, the electrode forming region 22e, the light emitting structure, and the structure are similar in form to the second electrode 40 as compared with the example of FIG. 4 of the third embodiment. The upper layer 42 extending portion 44 has a shape opened at the end of the first electrode 30 on the external connection portion 34 side. In the inner structure portion 25A sandwiched between the first electrodes 30, a primary extension portion 42A-1 extending in the width direction from the external connection portion 44 of the outer structure portion 25B and a secondary extension portion 42A extending in the longitudinal direction therefrom. -2 is provided. Further, the structure of the first electrode 30 and the formation region 22e are also different, and the external connection portion 34 is disposed at the longitudinal end portion of the light emitting structure portions 25A and 25B. This has a structure including an extending portion 44B extending in one direction toward the external connecting portion 44 side. In addition, the external connection portion 44 of the second electrode 40 is not in a one-to-one relationship with the longitudinal light emitting structure portions 25A and B arranged alternately with the first electrodes 30, but is on the outer light emitting structure portion 25B. Are provided respectively. Here, FIG. 6A is a schematic plan view of the light-emitting element. In addition, the dimensions of the light-emitting element in this example are □ 800 μm (800 μm square), and the dimensions of the other structures are the above examples except for the light-emitting structure related to the element size and the extension portion associated therewith. Is almost the same.

この例においても、本発明の電極構造は好適に機能し、上記実施形態3と同様に、閉塞した電極形成領域22eにおいても、露出部22sからの光取り出しを好適になし得る。尚、実施形態3及び4の例では、突起部について図示していないが、上記実施形態1〜2(図1,2,8)と同様に、露出部22s内で、電極と発光構造との間に突起部を設けても良い。   Also in this example, the electrode structure of the present invention functions suitably, and similarly to the third embodiment, light extraction from the exposed portion 22s can be suitably performed even in the closed electrode formation region 22e. In the examples of Embodiments 3 and 4, although the protrusions are not shown, the electrodes and the light emitting structures are exposed in the exposed portion 22s as in Embodiments 1 and 2 (FIGS. 1, 2 and 8). Protrusions may be provided between them.

(実施形態5)
図5の例では、実施形態3,4(図4,6)と同様に、延伸部及び発光構造部を複数有する構造であり、異なる点としては、実施形態4(図6)の構造部25Aに設けられた第2電極延伸部42Aと同様に、1つの延伸部34, 44が屈曲する様な形状、枝分かれる形状の構造を有し、更に、複数の発光構造部25A, Bに対して、各電極に1つの外部接続部34, 44が設けられた素子構造を有している。各電極30, 40の延伸部は、発光構造部25A, Bに並設される(2次)延伸部34B-2, 42B-2(42A-2)と、その2次延伸部まで配線し、各延伸部(発光構造部25A, B)間を配線する(1次)延伸部34B-1, 42-1と、を有する構造であり、外部接続部34, 44を基点として、それぞれ1次、2次延伸部を備えて、1つの外部接続部に接続されている。また、第1電極30の内側発光構造部25Aに挟まれた延伸部34Aは、1次延伸部だけで構成されている。
(Embodiment 5)
The example of FIG. 5 has a structure having a plurality of extending portions and light emitting structure portions as in the third and fourth embodiments (FIGS. 4 and 6). The difference is the structure portion 25A of the fourth embodiment (FIG. 6). Similarly to the second electrode extending portion 42A provided in the first electrode, the extending portion 34, 44 has a bent shape or a branched structure. Further, with respect to the plurality of light emitting structure portions 25A, B, Each element has an element structure in which one external connection portion 34, 44 is provided. The extended portions of the electrodes 30 and 40 are wired to (secondary) extended portions 34B-2 and 42B-2 (42A-2) arranged in parallel to the light emitting structure portions 25A and B, and to the secondary extended portions, (Primary) extending portions 34B-1 and 42-1 for wiring between the extending portions (light emitting structure portions 25A and B), and the primary connection and the external connection portions 34 and 44, respectively. A secondary extending part is provided and connected to one external connection part. Further, the extending portion 34A sandwiched between the inner light emitting structure portions 25A of the first electrode 30 is composed of only the primary extending portion.

このため、実施形態3,4(第1電極)とは異なり、実施形態4の第2電極上層42と同様に、第1,2電極の延伸部34, 44、第1電極30及び第2電極上層42は互いに分離されず、互いに接続され、また、そのような配線を可能とするために、各電極が設けられる発光構造、第1導電型層露出領域も、互いに接続された構造となっている。 また、実施形態2,3の例とは異なり、各発光構造部の長さが異なる構造となっているが、このような互いに接続された電極構造によりそれを補うことができ、好ましい。ここで、図5Aは、発光素子の平面図の概略であり、図5Bは5AのAA断面を示す概略断面図である。また、発光素子の外形寸法は、□600μm(600μm角)であり、その他の寸法は、素子の大きさに関わる発光構造及びそれに伴う延伸部を除いて、他の実施形態とほぼ同様である。   For this reason, unlike Embodiments 3 and 4 (first electrode), like the second electrode upper layer 42 of Embodiment 4, the extended portions 34 and 44 of the first and second electrodes, the first electrode 30 and the second electrode The upper layers 42 are not separated from each other but are connected to each other, and in order to enable such wiring, the light emitting structure provided with each electrode and the first conductivity type layer exposed region are also connected to each other. Yes. Unlike the examples of the second and third embodiments, the lengths of the light emitting structure portions are different from each other. However, such an electrode structure connected to each other can be supplemented, which is preferable. Here, FIG. 5A is a schematic plan view of the light-emitting element, and FIG. 5B is a schematic cross-sectional view showing a cross section AA of 5A. The external dimensions of the light-emitting element are □ 600 μm (600 μm square), and other dimensions are substantially the same as those of the other embodiments except for the light-emitting structure related to the element size and the accompanying extension.

この発光素子の例でも他の実施形態同様に、本発明の電極構造を好適に適用できる。特に、各延伸部は発光構造の内部深くにまで延伸しており、第1電極30の一部の延伸部(34B-2, 34A)における電極形成部22eは、一部が開口された凹欠部であっても、発光構造深部にまで設けられ、光閉じ込め作用が大きな形態となっているが、上記電極構造により、それを抑えて、好適な発光特性、電力効率をなし得る。図の例では、該凹欠部の一部延伸部は、突出部の長さ・幅は、ほぼ同一となって、上記他の形態と同様に第1,2層の幅中心をほぼ同一としている。また、上述したように電極各部において、第1,2層の幅中心を互いに変位させたり、突出部長さ・幅を相違させたり、また各部の間でこれらを互いに変位、異なるようにすることもできる。   Also in this example of the light emitting element, the electrode structure of the present invention can be suitably applied as in the other embodiments. In particular, each extended portion extends deep inside the light emitting structure, and the electrode forming portion 22e in the extended portion (34B-2, 34A) of the first electrode 30 has a notch that is partially opened. Even if it is a part, it is provided up to the deep part of the light emitting structure and has a large light confinement effect. However, with the above electrode structure, it is possible to suppress it and achieve suitable light emitting characteristics and power efficiency. In the example shown in the drawing, the length and width of the protruding portion of the partially extended portion of the concave portion are substantially the same, and the width centers of the first and second layers are substantially the same as in the other embodiments. Yes. In addition, as described above, in each part of the electrode, the width centers of the first and second layers can be displaced from each other, the length and width of the projecting part can be made different, and the parts can be displaced from each other and can be made different from each other. it can.

(実施形態6)
以上の発光素子100を搭載する発光装置200について説明すると、図7A,Bに示すように、実装用の基体・領域201の発光素子実装部173に発光素子100が載置された構造となる。実装基体として例えば、発光素子用、受光素子用のステム(図7Bの210)、平面実装用セラミック基板、プラスチック基板等が挙げられる。具体的にはAlNからなる実装基体、金属性の実装基体を用いると放熱性の高い発光装置を得ることができ好ましい。半導体発光素子が実装される実装面173は金属材料からなることで、発光素子外に取り出された光を反射し、好適な光指向性の発光装置とすることができる。実装面などの発光素子が載置され、光が到達する装置内部の表面、反射面203では、金属材料が例えばリード電極210などに用いられ、その金属材料は本発光装置の発光波長の光を高反射率で反射することのできる金属材料が好ましい。具体的には、Ag、Al、Rh等が挙げられ、鍍金被膜など形成される。発光装置の例は、図4に示すように、装置の基体・筐体220に設けられた素子実装部173に接着層160を介して、第2の主面に反射層などのメタライズ層170、共晶ハンダ、接着層180を設けた半導体発光素子100を熱圧着などで実装して、各電極にワイヤ250などで、発光装置200のリード電極210(a,b)とそれぞれ接続して、発光素子を封止部材230で封止した構造を有している。尚、図中の符号122〜124、110は、上記発光素子の各層22〜23及び基板10に相当する。図7Aでは発光装置200の基体220に各電極リード210が貫入されて、発光素子が載置される領域に露出されて、その電極接続部にワイヤ250で電気的に接続された構造となっており、更に、その露出領域を発光素子と共に封止する透光性の封止部材230、若しくは気密封止などにより封止された構造を有する。図7Bの例では、封止部材230が装置の基材を兼ねた構造となっている。封止部材としては、エポキシ樹脂、シリコーン樹脂、フッ素樹脂などの耐候性に優れた透明樹脂や硝子などが用いられ、接着部材180にはこれらの樹脂材料の他、共晶ハンダなどの半田,共晶材料、Agペーストなどが用いられる。
また、図4,5の例では断面図に示すように、基板の半導体構造に対向する面側にメタライズ層として、反射層70が設けられている。図7の例では、更にその上に、接着層180が設けられている。反射層は設けることで、光の反射性が向上する傾向にあり、好ましく、基板の第2の主面が露出した発光素子でも良い。尚、接着部材は、基板のメタライズ層に、基板側接着層として設ける形態でも良い。
また、封止部材230中など、発光装置200の発光素子から装置の出射口、例えば図7のレンズ部、との間の光路上に、発光素子の光を少なくとも一部変換する光変換部材を有して、種々の発光色を得ることもできる。光変換部材としては、青色LEDの白色発光に好適に用いられるYAG系蛍光体、珪酸塩蛍光体、近紫外〜可視光を黄色〜赤色域に変換する窒化物蛍光体などが挙げられる。特に、高輝度且つ長時間の使用時においてはYAG・TAGなどのガーネット構造の蛍光体、例えば(Re1-xSmx3(Al1-yGay512:Ce(0≦x<1、0≦y≦1、但し、Reは、Y,Gd,La,Tbなど、が好適に用いられる。窒化物系蛍光体、オキシナイトライド蛍光体としては、Sr−Ca−Si−N:Eu、Ca−Si−N:Eu、Sr−Si−N:Eu、Sr−Ca−Si−O−N:Eu、Ca−Si−O−N:Eu、Sr−Si−O−N:Euなどがあり、一般式LSi(2/3X+4/3Y):Eu若しくはLSi(2/3X+4/3Y−2/3Z):Eu(Lは、Sr、Ca、SrとCaのいずれか。)で表される。また、これらの蛍光体、他の蛍光体などを適宜用いることにより、所望の発光色の発光装置とすることができる。
(Embodiment 6)
The light emitting device 200 on which the above light emitting element 100 is mounted will be described. As shown in FIGS. 7A and 7B, the light emitting element 100 is mounted on the light emitting element mounting portion 173 of the mounting substrate / region 201. Examples of the mounting substrate include stems for light emitting elements and light receiving elements (210 in FIG. 7B), ceramic substrates for flat mounting, plastic substrates, and the like. Specifically, it is preferable to use a mounting substrate made of AlN or a metallic mounting substrate because a light emitting device with high heat dissipation can be obtained. Since the mounting surface 173 on which the semiconductor light emitting element is mounted is made of a metal material, the light extracted outside the light emitting element is reflected, and a light emitting device having a suitable light directivity can be obtained. A metal material is used for, for example, the lead electrode 210 on the surface inside the device on which a light emitting element such as a mounting surface is placed and the light reaches, and the reflective surface 203, and the metal material emits light of the emission wavelength of the light emitting device. Metal materials that can reflect with high reflectivity are preferred. Specifically, Ag, Al, Rh, etc. are mentioned, and a plating film etc. are formed. As shown in FIG. 4, an example of the light-emitting device includes a metallized layer 170 such as a reflective layer on the second main surface via an adhesive layer 160 on an element mounting portion 173 provided on the base / housing 220 of the device. The semiconductor light emitting element 100 provided with the eutectic solder and the adhesive layer 180 is mounted by thermocompression bonding or the like, and each electrode is connected to the lead electrode 210 (a, b) of the light emitting device 200 with the wire 250 or the like to emit light. The element is sealed with a sealing member 230. Reference numerals 122 to 124 and 110 in the figure correspond to the layers 22 to 23 and the substrate 10 of the light emitting element. In FIG. 7A, each electrode lead 210 penetrates into the base body 220 of the light emitting device 200, is exposed to a region where the light emitting element is placed, and is electrically connected to the electrode connecting portion with a wire 250. Furthermore, it has a structure in which the exposed region is sealed with a light-transmitting sealing member 230 that seals the light-emitting element together with the light emitting element, or an airtight sealing. In the example of FIG. 7B, the sealing member 230 has a structure that also serves as a base material of the apparatus. As the sealing member, transparent resin or glass having excellent weather resistance such as epoxy resin, silicone resin, fluororesin or the like is used. In addition to these resin materials, solder and co-crystal solder such as eutectic solder are used for the adhesive member 180. Crystal material, Ag paste, or the like is used.
4 and 5, a reflective layer 70 is provided as a metallized layer on the side of the substrate facing the semiconductor structure, as shown in the sectional view. In the example of FIG. 7, an adhesive layer 180 is further provided thereon. Providing the reflective layer tends to improve the light reflectivity, and is preferably a light emitting element in which the second main surface of the substrate is exposed. The adhesive member may be provided on the metallized layer of the substrate as a substrate-side adhesive layer.
Further, a light conversion member that converts at least part of the light of the light emitting element is provided on the optical path between the light emitting element of the light emitting device 200 and the exit of the device, for example, the lens portion of FIG. In addition, various emission colors can be obtained. Examples of the light conversion member include a YAG phosphor, a silicate phosphor suitably used for white light emission of a blue LED, and a nitride phosphor that converts near ultraviolet to visible light into a yellow to red region. In particular, the phosphor of garnet structure, such as a YAG · TAG at the time of high luminance and long-term use, for example, (Re 1-x Sm x) 3 (Al 1-y Ga y) 5 O 12: Ce (0 ≦ x <1, 0 ≦ y ≦ 1, where Re is preferably Y, Gd, La, Tb, etc. The nitride-based phosphor and the oxynitride phosphor are Sr—Ca—Si—N. : Eu, Ca-Si-N: Eu, Sr-Si-N: Eu, Sr-Ca-Si-ON: Eu, Ca-Si-ON: Eu, Sr-Si-O-N: Eu It includes the general formula L X Si Y N (2 / 3X + 4 / 3Y): Eu or L X Si Y O Z N ( 2 / 3X + 4 / 3Y-2 / 3Z): Eu (L is, Sr, Ca, Sr Or any of these phosphors and other phosphors as appropriate. More, it is possible to obtain a desired emission color of the light emitting device.

本発明の一実施形態に係る発光素子の平面概略図。1 is a schematic plan view of a light emitting device according to an embodiment of the present invention. 図1AのAA断面における断面概略図。FIG. 1B is a schematic sectional view taken along the line AA in FIG. 1A. 本発明の一実施形態に係る発光素子の平面概略図。1 is a schematic plan view of a light emitting device according to an embodiment of the present invention. 図2AのAA断面における断面概略図。FIG. 2B is a schematic sectional view taken along the line AA in FIG. 2A. 本発明の一実施形態に係る発光素子の断面概略図。1 is a schematic cross-sectional view of a light emitting device according to an embodiment of the present invention. 本発明の一実施形態に係る発光素子の断面概略図。1 is a schematic cross-sectional view of a light emitting device according to an embodiment of the present invention. 本発明の一実施形態に係る発光素子の平面概略図。1 is a schematic plan view of a light emitting device according to an embodiment of the present invention. 本発明の一実施形態に係る発光素子の断面概略図。1 is a schematic cross-sectional view of a light emitting device according to an embodiment of the present invention. 本発明の一実施形態に係る発光素子の平面概略図。1 is a schematic plan view of a light emitting device according to an embodiment of the present invention. 図4AのAA断面における断面概略図。FIG. 4B is a schematic sectional view taken along the line AA in FIG. 4A. 本発明の一実施形態に係る発光素子の平面概略図。1 is a schematic plan view of a light emitting device according to an embodiment of the present invention. 図5AのAA断面における断面概略図。FIG. 5B is a schematic sectional view taken along the line AA in FIG. 5A. 本発明の一実施形態に係る発光素子の平面概略図。1 is a schematic plan view of a light emitting device according to an embodiment of the present invention. 本発明の一実施形態に係る発光装置の断面概略図。1 is a schematic cross-sectional view of a light emitting device according to an embodiment of the present invention. 本発明の一実施形態に係る発光装置の断面概略図。1 is a schematic cross-sectional view of a light emitting device according to an embodiment of the present invention. 本発明の一実施形態に係る発光素子の平面概略図。1 is a schematic plan view of a light emitting device according to an embodiment of the present invention.

符号の説明Explanation of symbols

10:基板,10s:基板露出表面、20:半導体構造・積層構造,21:下地層,22:第1導電型層(n型層)(22s:第1導電型層,22a:凹欠部,22e:電極形成領域),23:活性層(発光層),24:第2導電型層(p型層)、25:発光構造(25p:構造部,25s:発光構造側面(電極側))、26:素子構造・領域、30:第1電極,31:第1層(31p:突出部、31a:発光構造側、31e:その反対側),32:第2層,33:外部接続部,34:延伸部、40:第2電極,41:下層側(オーミック電極(透光性)),42:パッド電極(上層),43:外部接続部,44:延伸部、50:保護膜(51w, 52w:開口部)、60:突起部,61:電極側の側面,62:上面,63:発光構造側の側面 10: substrate, 10s: substrate exposed surface, 20: semiconductor structure / laminated structure, 21: underlayer, 22: first conductivity type layer (n-type layer) (22s: first conductivity type layer, 22a: notched portion, 22e: electrode formation region), 23: active layer (light-emitting layer), 24: second conductivity type layer (p-type layer), 25: light-emitting structure (25p: structure part, 25s: light-emitting structure side surface (electrode side)), 26: element structure / region, 30: first electrode, 31: first layer (31p: protrusion, 31a: light emitting structure side, 31e: opposite side), 32: second layer, 33: external connection, 34 : Stretched part, 40: second electrode, 41: lower layer side (ohmic electrode (translucent)), 42: pad electrode (upper layer), 43: external connection part, 44: stretched part, 50: protective film (51w, 52w: opening), 60: protrusion, 61: electrode side surface, 62: top surface, 63: light emitting structure side surface

Claims (11)

第1,2導電型の半導体層を含む発光構造と、該発光構造から露出された第1導電型の半導体層と、該第1,2導電型層に各々設けられた第1,2電極と、を有し、
前記第1導電型半導体層の露出表面に設けられた第1電極が、第1層と、該第1層上に第1層より幅の狭い若しくは面積の小さい第2層と、を少なくとも有し、
前記発光構造の光に対して、前記第1層が透光性を、前記第2層が反射性を有する半導体発光素子。
A light emitting structure including first and second conductivity type semiconductor layers; a first conductivity type semiconductor layer exposed from the light emission structure; and first and second electrodes respectively provided on the first and second conductivity type layers; Have
The first electrode provided on the exposed surface of the first conductivity type semiconductor layer has at least a first layer and a second layer having a smaller width or smaller area than the first layer on the first layer. ,
A semiconductor light-emitting element in which the first layer is translucent and the second layer is reflective with respect to light of the light-emitting structure.
前記第1層が、少なくとも隣接する発光構造の方向に、前記第2層から突出した突出部を有する請求項1記載の半導体発光素子。 2. The semiconductor light emitting element according to claim 1, wherein the first layer has a protruding portion protruding from the second layer at least in a direction of an adjacent light emitting structure. 第1,2導電型の半導体層を含む発光構造と、該発光構造から露出された第1導電型の半導体層と、該第1,2導電型層に各々設けられた第1,2電極と、を有し、
前記第1導電型半導体層の露出表面に設けられた第1電極が、第1層と、該第1層上に第1層より幅の狭い若しくは面積の小さい第2層と、を少なくとも有し、前記第1層が透光性を、前記第2層が反射性を有すると共に、
前記電極形成面内において、前記発光構造間に前記第1電極が設けられ、該第1電極が、
隣接する発光構造側面と前記第1,2層端部との距離が、第1層より第2層が長くなるように設けられている半導体発光素子。
A light emitting structure including first and second conductivity type semiconductor layers; a first conductivity type semiconductor layer exposed from the light emission structure; and first and second electrodes respectively provided on the first and second conductivity type layers; Have
The first electrode provided on the exposed surface of the first conductivity type semiconductor layer has at least a first layer and a second layer having a smaller width or smaller area than the first layer on the first layer. The first layer is translucent and the second layer is reflective;
In the electrode formation surface, the first electrode is provided between the light emitting structures, and the first electrode is
A semiconductor light emitting element provided such that a distance between an adjacent light emitting structure side surface and an end of the first and second layers is longer than a first layer.
前記第1層の突出部が、前記第2層の外周の略全域に設けられている請求項1〜3のいずれか1項に記載の半導体発光素子。 The semiconductor light emitting element according to any one of claims 1 to 3, wherein the protruding portion of the first layer is provided in substantially the entire outer periphery of the second layer. 前記発光構造と前記第1電極との間に、該発光構造の発光部より高い突起部を有する請求項1〜4のいずれか1項に記載の半導体発光素子。 5. The semiconductor light emitting element according to claim 1, wherein a protrusion higher than the light emitting portion of the light emitting structure is provided between the light emitting structure and the first electrode. 前記突起部が、前記発光構造から分離された半導体構造を有する請求項5記載の半導体発光素子。 The semiconductor light emitting element according to claim 5, wherein the protrusion has a semiconductor structure separated from the light emitting structure. 前記突起部が前記発光構造と分離され、前記第1層が、前記突起部の第1電極側の側面に延在し、前記第2層が該突起部から離間している請求項5又は6記載の半導体発光素子。 The protrusion is separated from the light emitting structure, the first layer extends to a side surface of the protrusion on the first electrode side, and the second layer is separated from the protrusion. The semiconductor light emitting element as described. 前記第1電極の少なくとも一部が、前記第1導電型半導体層露出領域で前記発光構造内部へ凹んだ凹欠部に配置され、前記凹欠部が該第1電極の外周長の半分以上を囲む請求項1〜7のいずれか1項に記載の半導体発光素子。 At least a portion of the first electrode is disposed in a recessed portion that is recessed into the light emitting structure in the exposed region of the first conductivity type semiconductor layer, and the recessed portion has at least half of the outer peripheral length of the first electrode. The semiconductor light emitting element according to claim 1, wherein the semiconductor light emitting element is enclosed. 前記第1電極が外部接続部と、該外部接続部から延伸する延伸部と、を有し、該外部接続部及び延伸部に、前記第1,2層がそれぞれ設けられている請求項1〜8のいずれか1項に記載の半導体発光素子。 The first electrode has an external connection part and an extension part extending from the external connection part, and the first and second layers are provided in the external connection part and the extension part, respectively. 9. The semiconductor light emitting device according to any one of items 8. 請求項1〜9のいずれか1項に記載の半導体発光素子が、載置部に設けられた発光装置。 The light-emitting device with which the semiconductor light-emitting device of any one of Claims 1-9 was provided in the mounting part. 前記発光装置が、前記半導体発光素子を封止する封止部材を有し、該封止部材が、半導体発光素子の光の少なくとも一部を波長変換する光変換部材を有する請求項10記載の発光装置。 The light-emitting device according to claim 10, wherein the light-emitting device includes a sealing member that seals the semiconductor light-emitting element, and the sealing member includes a light conversion member that converts a wavelength of at least part of light of the semiconductor light-emitting element. apparatus.
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