200832735 ^ 九、發明說明： 【發明所屬之技術領域】 本發明係有關一種發光二極體，旨在提供一種可有效 改善第一型掺雜半導體層的蠢晶品質，並增加正向出射發 光二極體的光能量，因此能提高發光效率之發光二極體。 【先前技術】 按，由於發光二極體與傳統燈泡比較具有絕對的優 ⑩勢，例如體積小、壽命長、低電壓/電流驅動、不易破裂、 發光時無顯著之問題、不含水銀（沒有污染問題）、發光效 率佳（省電）等特性，且近幾年來發光二極體的發光效率不 斷提升，因此發光二極體在某些領域已漸漸取代日光燈與 白熱燈泡，例如需要高速反應的掃描器燈源、液晶顯示器 的月光源或fj光源^車的儀表板照明、交通號誌燈以及一 般的照明裝置等。 而且，由於含氮之ΠΙ-ν族化合物為一寬頻帶能隙之 ♦材料，其發光波長可以從紫外光一直涵蓋至紅光，可說是 幾乎涵蓋整個可見光的波段。因此，利用含氮化_化合 物半導體，如氮化鎵（GaN)、氮化鋁鎵（GaA1N)、氮化銦鎵 (GalnN)等的發光二極體元件以廣泛地應用在各種發光模 組中。 、 第圖係為習知發光二極體結構之剖面示意圖。如第 :圖所示，發光二極體1主要是由基板1 1、η型摻雜半 ¥體層1 2笔極1 2 1、發光層1 3、ρ型摻雜半導體 層1 4、歐姆接觸層15以及電極141所構成。其中，η 5 200832735 型摻雜半導體層1 2、發光層χ 3、p型摻雜半導體層工 4、歐姆接觸層15以及電極141是依序配置於基板1 1上，且發光層1 3僅覆蓋住部份的n型摻雜半導體層工 2上。 而一般基板大多使用的有藍寶石（Sapphire)、6H碳化 石夕（SiC)、坤化鎵(GaAs)或矽（Si)等材質，由於基板和η型 摻雜半導體層（如氮化鎵、氮化鋁鎵、氮化銦鎵）間晶格的 不匹配而產生的應變常引發晶格缺陷（DidocMion)的形 _ 成。此外，在習知發光二極體中，其結構常為異質結構， 由於其晶格不匹配及熱膨脹係數之差異，容易在異質介面 累積應變能，這些應變能在發光二極體製造及使用過程中 往往會形成晶格缺陷以釋放能量，部分晶格缺陷更會延伸 至晶體表面，被稱之為貫穿式缺陷（Threading Dislocation)。這些晶格缺陷往往是造成發光二極體退化 之主要原因，在已退化或失效之發光二極體上作顯微組織 分析時，經常可清晰地觀察到晶格缺陷的存在，這些晶格 • 缺陷一般由異質介面上開始產生，在元件活化區（Active Region)，倘有晶格缺陷之存在，則會成為少數載子 (Minority Carriers)之陷阱（Traps)或再結合中心 (Recombination Centers)，因而影響發光二極體的特性及 品質。例如晶格缺陷的存在使得過剩載子結合不以發光再 結合型態（Radiative Recombination)釋出能量，反而藉由 非輻射再結合效應（Nonradiative Recombination Effect) 將能量釋出。除了提供陷阱捕捉少數載子外，晶格缺陷也 提供載子濃度擴散的捷徑（Short Cut)，對一具有特定載子 6 200832735 分佈的元件而言，載子沿著晶格缺陷作快速擴散或是載子 偏聚於晶格缺陷附近，均會導致元件載子分佈的不均勻， 進而影響發光二極體之功能，並降低發光二極體之發光品 質。 【發明内容】 有鑑於此，本發明即在提供一種可有效改善第一型掺 雜半導體層的磊晶品質，增加晶格匹配性且降低晶格缺陷 • 密度，並增加正向出射發光二極體的光能量，因此能提高 發光效率之發光二極體。 為達上述目的，本發明之發光二極體至少包含有：一 矽基板、緩衝層、第一型掺雜半導體層、發光層以及第二 型掺雜半導體層，其緩衝層、第一型掺雜半導體層、發光 層以及第二型掺雜半導體層依序設於矽基板上方，且該矽 基板之其中一表面上係具有複數圖案，而緩衝層則覆蓋各 圖案上方，有效改善第一型掺雜半導體層的磊晶品質，以 • 提高發光二極體之發光效率。 【實施方式】 為能使貴審查委員清楚本發明之主要技術内容，以 及實施方式，茲配合圖式說明如下： 本發明「發光二極體」，如第二圖所示，該發光二極體 2係至少包含有： 一石夕基板2 1，該石夕基板2 1之其中一表面上係具有 複數圖案211，各圖案211係為凹入矽基板2 1表面 7 200832735 之凹洞或凹槽。 ^緩衝層22，係設置於該矽基板2丄上並覆蓋各圖 ^其緩衝層2 2可以為氣化辞或氮化石夕。 第—型掺雜半導體層2 3，係設置於緩衝層2 2上 方 I光層2 4，係設置於第一型掺雜半導體層2 2上 古兮ί—型掺雜半導體層2 5，係設置於發光層2 4上 二型摻雜半導體層2 3、該發光層2 4與該第二 材料卞，例^體層2 5之材質包括—⑴巧族化合物半導體 導體声2 上鎵、磷化鎵或磷砷化鎵，而第一型摻雜半 Ϊ ϋ3與弟二型摻雜半導體層2 5係為相反形式，如 =雜半導體層23為1型摻雜半導體層，而該第 一以半導體層25為一 ρ型摻雜半導 =體層23為一 _雜半導;:層二 摻雜+ ¥體層2 5為一 η型摻雜半導體層。 二電極2 3 1、2 5 1，係分則钟二士人 & 面以及第二型摻雜半導體層2 5之上‘面，H2 1底 垂直式排列，可增加發光二極體之發纽率Η電極形成 具體實施時，各圖案21 1之形成方輕可 板2 1進行乾式蝕刻或濕式蝕刻製成，其中:、、曰、土 侧選自硫酸、磷酸、確酸、氯氣酸 是以上的酸的任意混合，較佳义主^種或 歸）以固定比例（3 : 1)混合而成之與磷酸 基板21表面形成凹入之凹洞或凹槽，如第 8 200832735 圖术211係為凹洞之形式以週期性排列於矽基板21f 面，，鄰圖案211之間距(pitch)可介匕^ 二之:外，圖案211之直徑則可介於0.1…β之 :弟四圖所示’則為各圖案2 1 1形成凹槽之形 丄基板21上並覆蓋各圖案“ ”二：二―圖所不，在形成第-型掺雜半導體層 =1—型掺雜半導體層2 3是形成切基板2 1 表面但不完全填滿各1 ，而各個圖案2工 上可以抑制第-型掺雜半導體層2 3的局部性晶格缺陷且 I增加晶格匹配性，以改善第—型掺雜半導體層的遙晶品 貝一並曰加正向出射發光二極體的光能量，因此能提高發 光二極體之發光效率。 女上所述本兔明k供一種較佳可行之發光二極體， 爰依法提呈發明專利之中請；惟，以上之實施說明及圖式 所不，係本發明較佳實施例者，並非以此偈限本發明，是 以，舉凡與本發明之構造、裝置、特徵等近似、雷同者， 均應屬本發明之創設目的及申請專利範圍之内。 【圖式簡單說明】 第圖係為習知發光二極體結構之剖面示意圖。 第二圖係為本發明中發光二極體之剖面示意圖。 第三圖係為本發明中圖案之結構示意圖。 第四圖係為本發明中圖案之另一結構示意圖。 9 200832735 【主要元件代表符號說明】 1 發光二極體 1 1 基板 12——η型摻雜半導體層 12 1一電極 13 --發光層 14——ρ型摻雜半導體層 14 1一電極 # 15---歐姆接觸層 2 ---發光二極體 2 1 砍基板 211—圖案 2 2——緩衝層 2 3——第一型掺雜半導體層 2 3 1—電極 2 4--發光層 ❿ 2 5—一第二型掺雜半導體層 2 5 1一電極200832735 ^ IX. Description of the Invention: [Technical Field] The present invention relates to a light-emitting diode, which aims to provide an improved crystal quality of a first-type doped semiconductor layer and an increase in forward-emitting light emission. A light-emitting diode that increases the luminous efficiency of the polar body. [Prior Art] Press, because the light-emitting diode has an absolute superior potential compared with the conventional light bulb, such as small volume, long life, low voltage/current drive, not easy to break, no significant problems when emitting light, no mercury (no The pollution problem, the luminous efficiency (power saving) and other characteristics, and the luminous efficiency of the light-emitting diode has been increasing in recent years, so the light-emitting diode has gradually replaced the fluorescent lamp and the white heat bulb in some fields, for example, requiring high-speed reaction. Scanner light source, monthly light source of liquid crystal display or instrument panel illumination of fj light source, traffic signal light and general lighting device. Moreover, since the nitrogen-containing ytterbium-ν compound is a material having a wide band gap, the illuminating wavelength can be covered from ultraviolet light to red light, which is a band covering almost the entire visible light. Therefore, a light-emitting diode element including a nitride-containing compound semiconductor such as gallium nitride (GaN), aluminum gallium nitride (GaA1N), or indium gallium nitride (GalnN) is widely used in various light-emitting modules. . The figure is a schematic cross-sectional view of a conventional light-emitting diode structure. As shown in the figure: the light-emitting diode 1 is mainly composed of a substrate 1, an n-type doped body layer, a body electrode, a pen electrode 1, a light-emitting layer 13, a p-type doped semiconductor layer 14, and an ohmic contact. The layer 15 and the electrode 141 are formed. The η 5 200832735 type doped semiconductor layer 12, the luminescent layer χ 3, the p-type doped semiconductor layer 4, the ohmic contact layer 15 and the electrode 141 are sequentially disposed on the substrate 11 and the luminescent layer 13 is only Covering part of the n-type doped semiconductor layer 2 . In general, most of the substrates are made of sapphire, 6H carbon carbide (SiC), GaAs or bismuth (Si), due to the substrate and the n-type doped semiconductor layer (such as gallium nitride, nitrogen). The strain caused by the mismatch between the lattices of aluminum gallium and indium gallium nitride often causes the shape of the lattice defect (DidocMion). In addition, in the conventional light-emitting diodes, the structure is often a heterostructure. Due to the lattice mismatch and the difference in thermal expansion coefficient, it is easy to accumulate strain energy in the heterogeneous interface. These strain energy can be used in the manufacture and use of the light-emitting diode. Lattice defects are often formed to release energy, and some lattice defects extend to the crystal surface, which is called Threading Dislocation. These lattice defects are often the main cause of degradation of the light-emitting diodes. When performing microstructure analysis on degraded or failed LEDs, the presence of lattice defects is often clearly observed. Defects are generally generated by the heterogeneous interface. In the Active Region, if there are lattice defects, they will become the traps or the Recombination Centers of the Minority Carriers. Therefore, it affects the characteristics and quality of the light-emitting diode. For example, the presence of lattice defects allows the excess carrier binding to release energy without Radiative Recombination, but instead releases the energy by the Nonradiative Recombination Effect. In addition to providing traps to capture minority carriers, lattice defects also provide a short cut for carrier concentration diffusion. For a component with a specific carrier 6 200832735 distribution, the carrier rapidly diffuses along the lattice defects or When the carrier is segregated near the lattice defect, the distribution of the carrier of the component is uneven, which affects the function of the light-emitting diode and reduces the light-emitting quality of the light-emitting diode. SUMMARY OF THE INVENTION In view of the above, the present invention provides an improvement in epitaxial quality of a first type doped semiconductor layer, increase lattice matching, reduce lattice defects, density, and increase forward emission of light emitting diodes. The light energy of the body, thus improving the luminous efficiency of the light-emitting diode. To achieve the above objective, the light emitting diode of the present invention comprises at least: a germanium substrate, a buffer layer, a first type doped semiconductor layer, a light emitting layer, and a second type doped semiconductor layer, the buffer layer and the first type doped The impurity semiconductor layer, the light emitting layer and the second type doped semiconductor layer are sequentially disposed above the germanium substrate, and one of the surfaces of the germanium substrate has a plurality of patterns, and the buffer layer covers the top of each pattern, thereby effectively improving the first type The epitaxial quality of the doped semiconductor layer improves the luminous efficiency of the light-emitting diode. [Embodiment] In order to enable the reviewing committee to understand the main technical contents and embodiments of the present invention, the following description is given with reference to the following: "Light-emitting diode" of the present invention, as shown in the second figure, the light-emitting diode The second system includes at least one surface of the slab substrate 2, and a plurality of patterns 211 on the surface of the slab substrate 2, each pattern 211 being a recess or a recess recessed into the surface 7 200832735 of the ruthenium substrate 2 1 . The buffer layer 22 is disposed on the germanium substrate 2 and covers each of the layers. The buffer layer 2 2 may be a gasification word or a nitride stone. The first-type doped semiconductor layer 23 is disposed on the buffer layer 2 2 above the I-light layer 24, and is disposed on the first-type doped semiconductor layer 2 2 The second type doped semiconductor layer 23 on the light-emitting layer 24, the light-emitting layer 24 and the second material layer, the material of the body layer 25 includes - (1) gallium compound semiconductor conductor 2 on gallium, gallium phosphide Or phosphorous gallium arsenide, and the first type doped semiconductor layer 3 and the second type doped semiconductor layer 25 are in opposite forms, such as the = impurity semiconductor layer 23 is a type 1 doped semiconductor layer, and the first semiconductor is Layer 25 is a p-type doped semiconductor = body layer 23 is a hetero-a semiconductor; layer 2 doping + body layer 25 is an n-type doped semiconductor layer. The two electrodes 2 3 1 , 2 5 1 are divided into two parts: the second surface of the second and the doped semiconductor layer 25, and the H2 1 bottom is vertically arranged to increase the emission of the light emitting diode. When the formation of the Η electrode is performed, the formation of each pattern 21 1 is performed by dry etching or wet etching, wherein: , 曰, and the soil side are selected from the group consisting of sulfuric acid, phosphoric acid, acid, and chlorine acid. Any combination of the above acids, preferably in a fixed ratio (3:1), forming a concave cavity or groove with the surface of the phosphoric acid substrate 21, as shown in Fig. 8 200832735 The 211 is in the form of a concave hole to be periodically arranged on the surface of the 矽 substrate 21f, and the pitch between the adjacent patterns 211 can be referred to as two: outside, the diameter of the pattern 211 can be between 0.1...β: the fourth The figure shows that each pattern 2 1 1 forms a groove on the shape of the substrate 21 and covers each pattern " ” 2: 2 - Figure No., forming a first type doped semiconductor layer = 1 - doped semiconductor The layer 2 3 is formed on the surface of the cut substrate 2 1 but not completely filled with each 1 , and each pattern 2 can suppress the first-type doped semiconductor layer 23 Partial lattice defects and I increase lattice matching to improve the light energy of the first-type doped semiconductor layer and the light energy of the forward-emitting light-emitting diode, thereby improving the light-emitting diode Luminous efficiency. The present invention provides a preferred and feasible light-emitting diode for use in the present invention. However, the above description and drawings are not intended to be preferred embodiments of the present invention. The present invention is not limited thereto, and it should be construed that the structures, devices, features, and the like of the present invention are similar to those of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS The figure is a schematic cross-sectional view of a conventional light-emitting diode structure. The second figure is a schematic cross-sectional view of the light-emitting diode of the present invention. The third figure is a schematic structural view of the pattern in the present invention. The fourth figure is another schematic diagram of the structure of the present invention. 9 200832735 [Description of main component representative symbols] 1 Light-emitting diode 1 1 Substrate 12 - n-type doped semiconductor layer 12 1 - electrode 13 - light-emitting layer 14 - p-type doped semiconductor layer 14 1 - electrode # 15 --- Ohmic contact layer 2 --- Light-emitting diode 2 1 Cut substrate 211 - Pattern 2 2 - Buffer layer 2 3 - First type doped semiconductor layer 2 3 - Electrode 2 4--Light-emitting layer 2 5 - a second type doped semiconductor layer 2 5 1 an electrode