JPH04243183A - Semiconductor laser and manufacture thereof - Google Patents
Semiconductor laser and manufacture thereofInfo
- Publication number
- JPH04243183A JPH04243183A JP1702891A JP1702891A JPH04243183A JP H04243183 A JPH04243183 A JP H04243183A JP 1702891 A JP1702891 A JP 1702891A JP 1702891 A JP1702891 A JP 1702891A JP H04243183 A JPH04243183 A JP H04243183A
- Authority
- JP
- Japan
- Prior art keywords
- layer
- conductivity type
- optical waveguide
- cladding layer
- waveguide layer
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 239000004065 semiconductor Substances 0.000 title claims description 11
- 238000004519 manufacturing process Methods 0.000 title claims description 8
- 230000003287 optical effect Effects 0.000 claims abstract description 68
- 239000013078 crystal Substances 0.000 claims abstract description 14
- 238000005253 cladding Methods 0.000 claims description 50
- 230000000903 blocking effect Effects 0.000 claims description 19
- 239000000758 substrate Substances 0.000 claims description 13
- 229910001218 Gallium arsenide Inorganic materials 0.000 claims description 8
- 238000005530 etching Methods 0.000 claims description 4
- 238000000034 method Methods 0.000 description 10
- 230000010355 oscillation Effects 0.000 description 7
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 6
- NBIIXXVUZAFLBC-UHFFFAOYSA-N Phosphoric acid Chemical compound OP(O)(O)=O NBIIXXVUZAFLBC-UHFFFAOYSA-N 0.000 description 4
- 230000004888 barrier function Effects 0.000 description 4
- 229910052681 coesite Inorganic materials 0.000 description 3
- 229910052906 cristobalite Inorganic materials 0.000 description 3
- 238000005259 measurement Methods 0.000 description 3
- 239000000203 mixture Substances 0.000 description 3
- 239000002994 raw material Substances 0.000 description 3
- 239000000377 silicon dioxide Substances 0.000 description 3
- 235000012239 silicon dioxide Nutrition 0.000 description 3
- 229910052682 stishovite Inorganic materials 0.000 description 3
- 229910052905 tridymite Inorganic materials 0.000 description 3
- 229910000147 aluminium phosphate Inorganic materials 0.000 description 2
- RBFQJDQYXXHULB-UHFFFAOYSA-N arsane Chemical compound [AsH3] RBFQJDQYXXHULB-UHFFFAOYSA-N 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 230000010365 information processing Effects 0.000 description 2
- 238000002488 metal-organic chemical vapour deposition Methods 0.000 description 2
- 229920002120 photoresistant polymer Polymers 0.000 description 2
- XCZXGTMEAKBVPV-UHFFFAOYSA-N trimethylgallium Chemical compound C[Ga](C)C XCZXGTMEAKBVPV-UHFFFAOYSA-N 0.000 description 2
- 229910000530 Gallium indium arsenide Inorganic materials 0.000 description 1
- 238000010521 absorption reaction Methods 0.000 description 1
- 229910000070 arsenic hydride Inorganic materials 0.000 description 1
- 238000005229 chemical vapour deposition Methods 0.000 description 1
- 238000003776 cleavage reaction Methods 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 239000002019 doping agent Substances 0.000 description 1
- -1 hydride phosphine Chemical compound 0.000 description 1
- 230000031700 light absorption Effects 0.000 description 1
- 230000000737 periodic effect Effects 0.000 description 1
- 230000007017 scission Effects 0.000 description 1
- JLTRXTDYQLMHGR-UHFFFAOYSA-N trimethylaluminium Chemical compound C[Al](C)C JLTRXTDYQLMHGR-UHFFFAOYSA-N 0.000 description 1
- IBEFSUTVZWZJEL-UHFFFAOYSA-N trimethylindium Chemical compound C[In](C)C IBEFSUTVZWZJEL-UHFFFAOYSA-N 0.000 description 1
Abstract
Description
［発明の目的］ [Purpose of the invention]
【０００１】0001
【産業上の利用分野】本発明は、例えば光情報処理や光
計測等の光源に使用される半導体レ−ザ装置及びその製
造方法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor laser device used as a light source for optical information processing, optical measurement, etc., and a method for manufacturing the same.
【０００２】0002
【従来の技術】近年、短波長の半導体レ−ザ装置の開発
が進められ、この中でも、例えば ０．６μｍ 帯に発
振波長を持つＩｎＧａＡｌＰ赤色レ−ザは、従来のＨｅ
−Ｎｅガスレ−ザに替るものとして様々な応用の可能性
を持っており、例えば光情報処理や光計測の分野におい
て、小形軽量で低消費電力の光源を実現するキ−デバイ
スとして注目されている。[Prior Art] In recent years, the development of short-wavelength semiconductor laser devices has progressed, and among these, for example, an InGaAlP red laser with an oscillation wavelength in the 0.6 μm band has been developed compared to the conventional He
-It has the potential for various applications as an alternative to Ne gas lasers, and is attracting attention as a key device for realizing small, lightweight, and low power consumption light sources, for example in the fields of optical information processing and optical measurement. .
【０００３】この様な中、例えばＩｎＧａＡｌＰ赤色レ
−ザとして、ＧａＡｓ半導体基板上にＩｎＧａＡｌＰク
ラッド層とＩｎＧａＰ活性層を成長させて形成したリッ
ジストライプ型のＳＢＲ（Ｓｅｒｅｃｔｉｖｅｌｙ ｂ
ｕｒｉｅｄ ｒｉｄｇｅ ｗａｖｅｇｕｉｄｅ）レ−ザ
がある。Under these circumstances, for example, as an InGaAlP red laser, a ridge stripe type SBR (Selectively b) is developed by growing an InGaAlP cladding layer and an InGaP active layer on a GaAs semiconductor substrate.
There is a ridge waveguide (uried ridge waveguide) laser.
【０００４】しかし、このＳＢＲレ−ザにおいては構造
パラメ−タを適正に設定することによって基本横モ−ド
が得られるが、しかし縦モ−ドに関しては結晶の劈開面
をレ−ザ共振器としていることから、複数の縦モ−ドが
発振してしまう。このため、単一縦モ−ドを要する分野
、特に光計測の分野においては、ＳＢＲレ−ザで十分な
対応をすることができない。However, in this SBR laser, the fundamental transverse mode can be obtained by appropriately setting the structural parameters; however, regarding the longitudinal mode, the cleavage plane of the crystal is As a result, multiple longitudinal modes oscillate. For this reason, SBR lasers cannot be used satisfactorily in fields that require a single longitudinal mode, particularly in the field of optical measurement.
【０００５】一方、単一縦モ−ド発振が可能なレ−ザに
は、分布帰還部として、例えば回折格子を用いた分布帰
還型（Ｄｉｓｕｔｒｉｂｕｔｅｄ Ｆｅｅｄｂａｃｋ
：以下、ＤＦＢと略記する）レ−ザがあり、ＩｎＰ系及
びＧａＡｓ系の半導体レ−ザにおいて開発されており、
例えばＩｎＰ系ＤＦＢレ−ザでは、活性層をＩｎＧａＡ
ｓＰ、クラッド層をＩｎＰ、光導波路層をＩｎＧａＡｓ
Ｐで構成し、１．５５μｍ 帯等に発振波長を持つ高速
大容量光通信用のレ−ザとして実用化されているが、発
振波長が ０．６μｍ 帯のＩｎＧａＡｌＰ赤色レ−ザ
としては未だ開発されていない。On the other hand, a laser capable of single longitudinal mode oscillation has a distributed feedback type using, for example, a diffraction grating as a distributed feedback section.
:hereinafter abbreviated as DFB), which has been developed as an InP-based and GaAs-based semiconductor laser.
For example, in an InP-based DFB laser, the active layer is made of InGaA.
sP, cladding layer is InP, optical waveguide layer is InGaAs
Although it has been put into practical use as a laser for high-speed, large-capacity optical communications with an oscillation wavelength in the 1.55 μm band, it has not yet been developed as an InGaAlP red laser with an oscillation wavelength in the 0.6 μm band. It has not been.
【０００６】なお、ＤＦＢレ−ザは、活性層とクラッド
層の間に活性層よりバンドギャップが大きくてクラッド
層より小さい光導波路層を設け、この光導波路層に分布
帰還部を形成することにより、一般的には構成できるも
のであるとされている。[0006] The DFB laser is manufactured by providing an optical waveguide layer between the active layer and the cladding layer, the bandgap of which is larger than that of the active layer and smaller than that of the cladding layer, and by forming a distributed feedback section in this optical waveguide layer. , is generally considered to be configurable.
【０００７】それ故に、ＩｎＧａＡｌＰ系で、例えばＩ
ｎ０．５ Ｇａ０．５ Ｐ活性層を持つＳＢＲレ−ザに
おいてＤＦＢレ−ザ（以下、ＳＢＲ−ＤＦＢレ−ザと略
記する）を実現しようとする場合には、バンドギャップ
がＩｎ０．５ Ｇａ０．５ Ｐ活性層より大きくて、か
つＩｎ０．５ （Ｇａ１−ｘＡｌｘ）０．５ Ｐクラッ
ド層よりもＡｌが少なく、バンドギャップが小さいＩｎ
０．５ （Ｇａ１−ｙＡｌｙ）０．５ Ｐ光導波路層（
０＜ｙ＜ｘ≦１）を設け、この光導波路層上に分布帰還
部を構成する回折格子を作成することになる。Therefore, in the InGaAlP system, for example, I
When attempting to realize a DFB laser (hereinafter abbreviated as SBR-DFB laser) in an SBR laser having an n0.5 Ga0.5 P active layer, the band gap is In0.5 Ga0. 5 In that is larger than the P active layer, contains less Al than the In0.5 (Ga1-xAlx)0.5 P cladding layer, and has a smaller band gap.
0.5 (Ga1-yAly)0.5 P optical waveguide layer (
0<y<x≦1), and a diffraction grating constituting a distributed feedback section is created on this optical waveguide layer.
【０００８】このようなＩｎＧａＡｌＰ系のＳＢＲ−Ｄ
ＦＢレ−ザを得ようとする場合には、通信用として実用
化しているＩｎＰ系ＤＦＢレ−ザの一つの構成をそのま
ま倣えば、以下に記載するような構成のものになると考
えられる。これを図９を参照して説明する。なお、図９
は形成途中の装置要部を示す斜視図である。[0008] Such an InGaAlP-based SBR-D
When attempting to obtain an FB laser, it is thought that if one structure of an InP-based DFB laser that has been put into practical use for communications is imitated as it is, the structure as described below will be obtained. This will be explained with reference to FIG. In addition, Figure 9
FIG. 2 is a perspective view showing the main parts of the device in the process of being formed.
【０００９】すなわち、ｎ型ＧａＡｓ基板１上にｎ型Ｉ
ｎ０．５ （Ｇａ１−ｘＡｌｘ）０．５ Ｐクラッド層
２、Ｉｎ０．５ Ｇａ０．５ Ｐ活性層３、ｐ型Ｉｎ０
．５ （Ｇａ１−ｘＡｌｘ）０．５ Ｐバリア層４、ｐ
型Ｉｎ０．５ （Ｇａ１−ｙＡｌｙ）０．５ Ｐ光導波
路層５（０＜ｙ＜ｘ≦１）を順に連続成長する。That is, an n-type I layer is formed on an n-type GaAs substrate 1.
n0.5 (Ga1-xAlx)0.5 P cladding layer 2, In0.5 Ga0.5 P active layer 3, p-type In0
．． 5 (Ga1-xAlx)0.5 P barrier layer 4, p
A type In0.5 (Ga1-yAly)0.5 P optical waveguide layer 5 (0<y<x≦1) is successively grown in this order.
【００１０】その後、ｐ型光導波路層５上に回折格子６
を作成し、さらにその上にｐ型Ｉｎ０．５ （Ｇａ１−
ｘＡｌｘ）０．５ Ｐクラッド層７を成長させ、このｐ
型クラッド層７を、その上面にマスク８を設けてエッチ
ングしてストライプ状のリッジ９を形成する。なおリッ
ジ９を形成した後はｎ型ＧａＡｓ電流阻止層、ｐ型Ｇａ
Ａｓコンタクト層を成長させ、ｐ型コンタクト層の上面
とｎ型基板１の下面に電極を形成すればよい。After that, a diffraction grating 6 is formed on the p-type optical waveguide layer 5.
was created, and p-type In0.5 (Ga1-
xAlx)0.5 A P cladding layer 7 is grown, and this p
A mask 8 is provided on the upper surface of the mold cladding layer 7 and etched to form a striped ridge 9. Note that after forming the ridge 9, an n-type GaAs current blocking layer and a p-type GaAs current blocking layer are formed.
It is sufficient to grow an As contact layer and form electrodes on the upper surface of the p-type contact layer and the lower surface of the n-type substrate 1.
【００１１】しかしながら、上記の構成においてはｐ型
クラッド層７とｐ型光導波路層５とはＡｌ組成は異なる
ものの、両者とも同じＩｎＧａＡｌＰ四元混晶であるた
め、リッジ９を形成するためにｐ型クラッド層７のみを
エッチングしようとしても、再現性よく選択エッチング
することは非常に困難で、ｐ型光導波路層５をもエッチ
ングしてしまうことが生じる。このため上述の構成では
、赤色の単一モ−ドのレ−ザ光を発振する特性の均一な
ＩｎＧａＡｌＰ系のＳＢＲ−ＤＦＢレ−ザを製造性よく
、高い歩留のもとで得ることができない。However, in the above structure, although the p-type cladding layer 7 and the p-type optical waveguide layer 5 have different Al compositions, they are both made of the same InGaAlP quaternary mixed crystal. Even if an attempt is made to etch only the type cladding layer 7, it is very difficult to perform selective etching with good reproducibility, and the p-type optical waveguide layer 5 may also be etched. Therefore, with the above configuration, it is possible to obtain an InGaAlP-based SBR-DFB laser with uniform characteristics that oscillates red single-mode laser light with good manufacturability and high yield. Can not.
【００１２】0012
【発明が解決しようとする課題】上記のような特性の均
一な単一モ−ドのレ−ザ光を発振するレ−ザを得ること
が困難な状況に鑑みて本発明はなされたもので、その目
的とするところは、安定した発振を行なうことができ、
また製造性がよくて歩留が高く、特性が均一な半導体レ
−ザ装置及びその製造方法を提供することにある。[Problems to be Solved by the Invention] The present invention has been made in view of the situation where it is difficult to obtain a laser that oscillates a single mode laser beam with uniform characteristics as described above. , its purpose is to be able to perform stable oscillation,
Another object of the present invention is to provide a semiconductor laser device with good manufacturability, high yield, and uniform characteristics, and a method for manufacturing the same.
【００１３】［発明の構成］[Configuration of the invention]
【００１４】[0014]
【課題を解決するための手段】本発明の半導体レ−ザ装
置及びその製造方法は、第１導電型基板と、この第１導
電型基板上に少なくとも成層された第１導電型クラッド
層、ノンド−プ活性層、第２導電型光導波路層と、この
第２導電型光導波路層上の一部に形成されたこの第２導
電型光導波路層とは異元混晶のストライプ状リッジの第
２導電型クラッド層と、第２導電型光導波路層と第２導
電型クラッド層との界面に形成された分布帰還部と、第
２導電型光導波路層上の残部に第２導電型クラッド層に
隣接して成層された第１導電型電流阻止層と、この第１
導電型電流阻止層と第２導電型クラッド層上に形成され
た第２導電型コンタクト層とを具備して成ることを特徴
とするものであり、また、第１導電型基板上に、第１導
電型クラッド層、ノンド−プ活性層、第２導電型光導波
路層を成長形成する工程と、第２導電型光導波路層上面
に分布帰還部を形成する工程と、分布帰還部が形成され
た第２導電型光導波路層上に、第２導電型光導波路層と
は異元混晶の第２導電型クラッド層を成長形成する工程
と、第２導電型光導波路層をエッチングしないエッチャ
ントを用いて第２導電型クラッド層の一部のみをエッチ
ングして除去し、第２導電型光導波路層上に光導波路方
向に長手方向を有するストライプ状リッジを形成する工
程と、第２導電型光導波路層上の第２導電型クラッド層
を除去した部分に第１導電型電流阻止層を成長形成する
工程と、第２導電型クラッド層の残部及び第１導電型電
流阻止層の上に第２導電型コンタクト層を成長形成する
工程とを含むことを特徴とするものである。[Means for Solving the Problems] A semiconductor laser device and a method for manufacturing the same according to the present invention include a first conductivity type substrate, a first conductivity type cladding layer layered at least on the first conductivity type substrate, and a non-conductivity type cladding layer formed on the first conductivity type substrate. - active layer, second conductivity type optical waveguide layer, and this second conductivity type optical waveguide layer formed on a part of the second conductivity type optical waveguide layer are the striped ridges of the heterogeneous mixed crystal. a second conductivity type cladding layer, a distributed feedback part formed at the interface between the second conductivity type optical waveguide layer and the second conductivity type cladding layer, and a second conductivity type cladding layer in the remaining part on the second conductivity type optical waveguide layer. a first conductivity type current blocking layer layered adjacent to the first conductivity type current blocking layer;
It is characterized by comprising a conductivity type current blocking layer and a second conductivity type contact layer formed on the second conductivity type cladding layer, and a first conductivity type contact layer formed on the first conductivity type substrate. A step of growing a conductive cladding layer, a non-doped active layer, and a second conductive optical waveguide layer, a step of forming a distributed feedback section on the upper surface of the second conductive optical waveguide layer, and a step of forming the distributed feedback section. A step of growing a second conductivity type cladding layer of a heterogeneous mixed crystal different from the second conductivity type optical waveguide layer on the second conductivity type optical waveguide layer, and using an etchant that does not etch the second conductivity type optical waveguide layer. etching and removing only a part of the second conductivity type cladding layer to form a striped ridge having a longitudinal direction in the optical waveguide direction on the second conductivity type optical waveguide layer; growing a first conductivity type current blocking layer on the portion of the layer where the second conductivity type cladding layer has been removed; and growing a second conductivity type current blocking layer on the remaining portion of the second conductivity type cladding layer and the first conductivity type current blocking layer. The method is characterized in that it includes a step of growing and forming a mold contact layer.
【００１５】[0015]
【作用】上記のように構成された半導体レ−ザ装置及び
その製造方法は、分布帰還部が形成された光導波路層と
リッジを形成するクラッド層とを互いに異元混晶で作ら
れたものとし、これを光導波路層上に分布帰還部を形成
した後、その上にクラッド層を成層し、光導波路層をエ
ッチングしないエッチャントによってクラッド層のみを
選択エッチングして光導波路方向に延びるリッジを光導
波路層上に形成するようにしている。[Operation] The semiconductor laser device configured as described above and the manufacturing method thereof are such that the optical waveguide layer in which the distributed feedback portion is formed and the cladding layer forming the ridge are made of a heterogeneous mixed crystal. After forming a distributed feedback section on the optical waveguide layer, a cladding layer is formed on the cladding layer, and only the cladding layer is selectively etched using an etchant that does not etch the optical waveguide layer to form a ridge extending in the direction of the optical waveguide. It is formed on the wave layer.
【００１６】このため容易に光導波路層上に所定の発振
波長に応じた分布帰還部を形成することができ、また、
分布帰還部の上に光導波路層とは異元混晶のクラッド層
を成層し、異元混晶のため光導波路層はエッチングしな
いエッチャントによって、クラッド層のみを選択エッチ
ングしてリッジを再現性良く形成することができる。こ
のエッチングによっての光導波路層の形状変化はなく、
リッジを形成した後、光導波路層上に成層する電流阻止
層も、光導波路層及びリッジに対し良好なものとなる。
そして単一モ−ドのレ−ザ光の安定した発振が行え、特
性が均一なものが高い製造歩留で得ることができる。Therefore, a distributed feedback section corresponding to a predetermined oscillation wavelength can be easily formed on the optical waveguide layer, and
A cladding layer of a heterogeneous mixed crystal, which is different from the optical waveguide layer, is layered on the distributed feedback section, and only the cladding layer is selectively etched using an etchant that does not etch the optical waveguide layer because it is a heterogeneous mixed crystal, to form a ridge with good reproducibility. can be formed. There is no change in the shape of the optical waveguide layer due to this etching.
After the ridge is formed, the current blocking layer formed on the optical waveguide layer is also suitable for the optical waveguide layer and the ridge. Stable oscillation of a single mode laser beam can be performed, and a product with uniform characteristics can be obtained at a high manufacturing yield.
【００１７】[0017]
【実施例】以下、本発明の一実施例を図面を参照して説
明する。図１乃至図８は製造過程を工程順に示す工程図
である。DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. 1 to 8 are process diagrams showing the manufacturing process in order of process.
【００１８】図１に示す第１の工程において、原料とし
てメタル系 ＩＩＩ族有機金属のトリメチルインジウム
（（ＣＨ３ ）３ Ｉｎ），トリメチルガリウム（（Ｃ
Ｈ３ ）３ Ｇａ），トリメチルアルミニウム（（ＣＨ
３ ）３ Ａｌ）と、Ｖ族水素化物のホスフィン（ＰＨ
３ ）とを使用して大気圧未満に減圧した状態でのＭＯ
ＣＶＤ法によって、ｎ型ＧａＡｓ基板１１上に順次下層
から厚さ ０．９μｍ のｎ型Ｉｎ０．５ （Ｇａ０．
３ Ａｌ０．７ ）０．５ Ｐクラッド層１２、厚さ０
．０５μｍ のノンド−プＩｎ０．５ Ｇａ０．５ Ｐ
活性層１３、厚さ ０．２μｍ のｐ型Ｉｎ０．５ （
Ｇａ０．３ Ａｌ０．７ ）０．５ Ｐバリア層１４、
厚さ ０．１μｍ のｐ型Ｉｎ０．５ Ｇａ０．５ Ｐ
光導波路層１５を、原料組成を各適正に調整して連続成
長させる。この工程でｐ型光導波路層１５にはＺｎをド
−パントとして用い、これを４×１０１７ｃｍ−３の濃
度でド−プしてある。In the first step shown in FIG. 1, trimethylindium ((CH3)3In) and trimethylgallium ((C
H3 )3 Ga), trimethylaluminum ((CH
3)3Al) and the group V hydride phosphine (PH
3) MO under reduced pressure below atmospheric pressure using
Using the CVD method, n-type In0.5 (Ga0.
3 Al0.7)0.5 P cladding layer 12, thickness 0
．． 05 μm non-doped In0.5 Ga0.5 P
The active layer 13 is made of p-type In0.5 with a thickness of 0.2 μm (
Ga0.3 Al0.7 )0.5 P barrier layer 14,
P-type In0.5 Ga0.5 P with a thickness of 0.1 μm
The optical waveguide layer 15 is grown continuously by appropriately adjusting the raw material composition. In this step, the p-type optical waveguide layer 15 is doped with Zn as a dopant at a concentration of 4.times.10@17 cm@-3.
【００１９】なお、ｐ型光導波路層１５はアクセプタ濃
度が増加することによってバンドギャップが大きくなり
、吸収端波長が短くなってノンド−プ活性層１３から発
振するレ−ザ光に対して透明になり、光導波路層として
働くため、アクセプタ濃度としては２×１０１７ｃｍ−
３以上であることが望ましい。It should be noted that the p-type optical waveguide layer 15 becomes transparent to the laser beam oscillated from the non-doped active layer 13 because the band gap becomes larger as the acceptor concentration increases and the absorption edge wavelength becomes shorter. Since it works as an optical waveguide layer, the acceptor concentration is 2 x 1017 cm-
It is desirable that it is 3 or more.
【００２０】図２に示す第２の工程において、ｐ型光導
波路層１５の上面にホトレジストを塗布してホトレジス
トの膜を形成し、この膜に二光束干渉露光装置を用いて
露光処理等行って周期が０．１９２ μｍ の回折格子
のレジスト像１６を形成する。In the second step shown in FIG. 2, a photoresist is applied to the upper surface of the p-type optical waveguide layer 15 to form a photoresist film, and this film is exposed using a two-beam interference exposure device. A resist image 16 of a diffraction grating with a period of 0.192 μm is formed.
【００２１】図３に示す第３の工程において、前工程で
レジスト像１６が形成されたｐ型光導波路層１５の上面
をレジスト像をマスクとして化学エッチングし、ｐ型光
導波路層１５上に平行な等周期の凹凸を形成して回折格
子１７を転写し、分布帰還部を形成する。In the third step shown in FIG. 3, the upper surface of the p-type optical waveguide layer 15 on which the resist image 16 was formed in the previous step is chemically etched using the resist image as a mask, so that the upper surface of the p-type optical waveguide layer 15 is etched parallel to the p-type optical waveguide layer 15. The diffraction grating 17 is transferred by forming irregularities with equal periods, thereby forming a distributed feedback section.
【００２２】図４に示す第４の工程において、回折格子
１７が転写されたｐ型光導波路層１５上に、図１の第１
の工程と同様にして減圧ＭＯＣＶＤ法により厚さ ０．
７μｍ のｐ型Ｉｎ０．５ （Ｇａ０．３ Ａｌ０．７
）０．５ Ｐクラッド層１８を成長させる。In the fourth step shown in FIG. 4, the first layer shown in FIG.
The thickness was reduced to 0.0 by the low-pressure MOCVD method in the same manner as in the process described above.
7 μm p-type In0.5 (Ga0.3 Al0.7
) 0.5 P cladding layer 18 is grown.
【００２３】図５に示す第５の工程において、ｐ型クラ
ッド層１８の上面に、回折格子１７の周期方向に長手方
向を有する幅５μｍ のストライプ状のＳｉＯ２ 膜１
９を形成する。In the fifth step shown in FIG. 5, a striped SiO2 film 1 with a width of 5 μm having a longitudinal direction in the periodic direction of the diffraction grating 17 is formed on the upper surface of the p-type cladding layer 18.
form 9.
【００２４】図６に示す第６の工程において、ＳｉＯ２
膜１９をマスクとし、燐酸系のエッチャントを用いて
ｐ型クラッド層１８をｐ型光導波路層１５の上面まで選
択エッチングする。そして幅３μｍ のストライプ状の
リッジ２０を形成する。この時、燐酸系のエッチャント
を用いているために、四元混晶であるｐ型クラッド層１
８のみがエッチングされ、ｐ型クラッド層１８と異なり
ＩｎＧａＰの三元混晶であるｐ型光導波路層１５はエッ
チングされない。In the sixth step shown in FIG.
Using the film 19 as a mask, the p-type cladding layer 18 is selectively etched to the upper surface of the p-type optical waveguide layer 15 using a phosphoric acid-based etchant. Then, a striped ridge 20 with a width of 3 μm is formed. At this time, since a phosphoric acid-based etchant is used, the p-type cladding layer 1, which is a quaternary mixed crystal,
Unlike the p-type cladding layer 18, the p-type optical waveguide layer 15, which is a ternary mixed crystal of InGaP, is not etched.
【００２５】図７に示す第７の工程において、リッジ２
０上にＳｉＯ２膜１９のマスクを残したまま、ｐ型クラ
ッド層１８が除去されて回折格子１７が露出したｐ型光
導波路層１５上に、原料としてトリメチルガリウムとア
ルシン（ＡｓＨ３ ）とを使用して大気圧未満に減圧し
た状態でのＭＯＣＶＤ法によりｎ型ＧａＡｓ電流阻止層
２１をリッジ２０よりも厚く成長させ、その後、リッジ
２０上のＳｉＯ２ 膜１９を除去する。In the seventh step shown in FIG.
Trimethylgallium and arsine (AsH3) are used as raw materials on the p-type optical waveguide layer 15, where the p-type cladding layer 18 is removed and the diffraction grating 17 is exposed, while the mask of the SiO2 film 19 remains on the layer 15. The n-type GaAs current blocking layer 21 is grown to be thicker than the ridge 20 by MOCVD under reduced pressure below atmospheric pressure, and then the SiO2 film 19 on the ridge 20 is removed.
【００２６】図８に示す第８の工程において、前工程と
同様にして減圧ＭＯＣＶＤ法により、リッジ２０及びｎ
型電流阻止層２１の上面にｐ型ＧａＡｓコンタクト層２
２を成長させる。そしてｐ型コンタクト層２２の上面に
ｐ型電極２３を、ｎ型基板１１の下面にｎ型電極２４を
形成してレ−ザ用ウェハを作成した。In the eighth step shown in FIG. 8, the ridges 20 and n
A p-type GaAs contact layer 2 is formed on the upper surface of the type current blocking layer 21.
Grow 2. Then, a p-type electrode 23 was formed on the upper surface of the p-type contact layer 22, and an n-type electrode 24 was formed on the lower surface of the n-type substrate 11, thereby producing a laser wafer.
【００２７】さらに得られたウエハを、リッジ２０の長
手方向に直行する方向の面で劈開し、劈開面を反射面と
するＳＢＲ−ＤＦＢレ−ザを作成した。なお、このレ−
ザでは、ｎ型電流阻止層２１が、リッジ２０が形成され
ていない部分でノンド−プ活性層１３の上方の近接した
位置におかれ、ｎ型電流阻止層２１は光吸収層として働
くため、リッジ２０とリッジ２０以外の部分との間で複
素屈折率の差が生じ、これにより水平方向の光閉じ込め
が行われ、またｎ型電流阻止層２１は電流も阻止するの
で、しきい値は低い値となる。Further, the obtained wafer was cleaved at a plane perpendicular to the longitudinal direction of the ridge 20, and an SBR-DFB laser was fabricated using the cleaved plane as a reflective surface. In addition, this lane
In this case, the n-type current blocking layer 21 is placed above and close to the non-doped active layer 13 in a portion where the ridge 20 is not formed, and the n-type current blocking layer 21 functions as a light absorption layer. A difference in complex refractive index occurs between the ridge 20 and a portion other than the ridge 20, and this causes horizontal optical confinement, and the n-type current blocking layer 21 also blocks current, so the threshold is low. value.
【００２８】ここで作成したＳＢＲ−ＤＦＢレ−ザの特
性を測定したところ、しきい値は３０ｍＡと低い値とな
っており、また１０ｍＷ以上まで安定した良好な単一モ
−ドの赤色レ−ザ光の発振を行うことができた。なお効
率やキンクレベル等の特性も良好なものであった。When the characteristics of the SBR-DFB laser created here were measured, the threshold value was as low as 30 mA, and it was a good single mode red laser stable up to 10 mW or more. We were able to oscillate light. Furthermore, characteristics such as efficiency and kink level were also good.
【００２９】尚、本発明は上記の実施例にのみ限定され
るものではなく、原料として成層可能な他の組成のもの
を用いてもよく、またクラッド層及びバリア層をＩｎ０
．５ （Ｇａ１−ｘＡｌｘ）０．５ Ｐとし、ｘを０＜
ｘ≦１の関係にあるようにしてもよく、さらにバリア層
を特に独立して形成する要はない。そしてＩｎＧａＡｌ
Ｐ系に限らず他の混晶系でもよく、またエッチャントも
クラッド層はエッチングし、光導波路層はエッチングし
ないものを、各層の構成によって選定すればよい等、要
旨を逸脱しない範囲内で適宜変更して実施し得るもので
ある。It should be noted that the present invention is not limited to the above-mentioned embodiments; other compositions that can be layered may be used as raw materials, and the cladding layer and barrier layer may be made of In0.
．． 5 (Ga1-xAlx)0.5 P, x is 0<
The relationship x≦1 may be satisfied, and there is no particular need to form the barrier layer independently. and InGaAl
It is not limited to P-based, but other mixed crystal systems may be used, and the etchant may be selected depending on the configuration of each layer, such as one that etches the cladding layer but does not etch the optical waveguide layer. Changes may be made as appropriate within the scope of the gist. It can be implemented by
【００３０】[0030]
【発明の効果】以上の説明から明らかなように、本発明
は、分布帰還部が形成された光導波路層とリッジを形成
するクラッド層とを互いに異元混晶で作られるような構
成としたことにより、単一モ−ドのレ−ザ光の発振を安
定して行なうことができ、特性も均一であるものが得ら
れ、また製造性が良好で高い歩留での製造が実現できる
などの効果がある。[Effects of the Invention] As is clear from the above description, the present invention has a structure in which the optical waveguide layer in which the distributed feedback portion is formed and the cladding layer forming the ridge are made of heterogeneous mixed crystals. As a result, it is possible to stably oscillate a single mode laser beam with uniform characteristics, and it is also possible to achieve good manufacturability and high yield. There is an effect.
【図１】本発明の一実施例における第１の工程を示す斜
視図である。FIG. 1 is a perspective view showing a first step in an embodiment of the present invention.
【図２】図１の第１の工程に続く第２の工程を示す斜視
図である。FIG. 2 is a perspective view showing a second step following the first step in FIG. 1;
【図３】図２の第２の工程に続く第３の工程を示す斜視
図である。FIG. 3 is a perspective view showing a third step following the second step in FIG. 2;
【図４】図３の第３の工程に続く第４の工程を示す斜視
図である。FIG. 4 is a perspective view showing a fourth step following the third step in FIG. 3;
【図５】図４の第４の工程に続く第５の工程を示す斜視
図である。5 is a perspective view showing a fifth step following the fourth step in FIG. 4. FIG.
【図６】図５の第５の工程に続く第６の工程を示す斜視
図である。6 is a perspective view showing a sixth step following the fifth step in FIG. 5. FIG.
【図７】図６の第６の工程に続く第７の工程を示す斜視
図である。7 is a perspective view showing a seventh step following the sixth step in FIG. 6. FIG.
【図８】図７の第７の工程に続く第８の工程を示す斜視
図である。8 is a perspective view showing an eighth step following the seventh step in FIG. 7. FIG.
【図９】従来の技術における形成途中の装置要部を示す
斜視図である。FIG. 9 is a perspective view showing the main parts of a device in the process of being formed in a conventional technique.
１１ 基板 １２ ｎ型クラッド層 １３ ノンド−プ活性層 １５ ｐ型光導波路層 １７ 回折格子（分布帰還部） １８ ｐ型クラッド層 ２０ リッジ ２１ ｎ型電流阻止層 ２２ ｐ型コンタクト層 11 Board 12 N-type cladding layer 13 Non-doped active layer 15 p-type optical waveguide layer 17 Diffraction grating (distributed feedback part) 18 p-type cladding layer 20 Ridge 21 N-type current blocking layer 22 p-type contact layer
Claims (3)
板上に少なくとも成層された第１導電型クラッド層、ノ
ンド−プ活性層、第２導電型光導波路層と、この第２導
電型光導波路層上の一部に形成されたこの第２導電型光
導波路層とは異元混晶のストライプ状リッジの第２導電
型クラッド層と、前記第２導電型光導波路層と前記第２
導電型クラッド層との界面に形成された分布帰還部と、
前記第２導電型光導波路層上の残部に前記第２導電型ク
ラッド層に隣接して成層された第１導電型電流阻止層と
、この第１導電型電流阻止層と前記第２導電型クラッド
層上に形成された第２導電型コンタクト層とを具備して
成ることを特徴とする半導体レ−ザ装置。1. A first conductivity type substrate, a first conductivity type cladding layer, a non-doped active layer, a second conductivity type optical waveguide layer, which are formed at least on the first conductivity type substrate, and the second conductivity type substrate. The second conductivity type optical waveguide layer formed on a part of the second conductivity type optical waveguide layer is a second conductivity type cladding layer of a striped ridge of heterogeneous mixed crystal, the second conductivity type optical waveguide layer, and the second conductivity type optical waveguide layer. 2
A distributed feedback part formed at the interface with the conductive cladding layer,
a first conductivity type current blocking layer layered adjacent to the second conductivity type cladding layer on the remaining portion on the second conductivity type optical waveguide layer; this first conductivity type current blocking layer and the second conductivity type cladding layer; 1. A semiconductor laser device comprising: a second conductivity type contact layer formed on the second conductivity type contact layer.
．５ （Ｇａ１−ｘ Ａｌｘ ）０．５ Ｐ（０＜ｘ≦
１）、活性層がＩｎ０．５ Ｇａ０．５ Ｐ、光導波路
層がＩｎ０．５ Ｇａ０．５ Ｐからなることを特徴と
する請求項１記載の半導体レ−ザ装置。[Claim 2] The substrate is GaAs and the cladding layer is In0.
．． 5 (Ga1-x Alx )0.5 P(0<x≦
1) The semiconductor laser device according to claim 1, wherein the active layer is made of In0.5 Ga0.5 P and the optical waveguide layer is made of In0.5 Ga0.5 P.
層、ノンド−プ活性層、第２導電型光導波路層を成長形
成する工程と、前記第２導電型光導波路層上面に分布帰
還部を形成する工程と、分布帰還部が形成された前記第
２導電型光導波路層上に、前記第２導電型光導波路層と
は異元混晶の第２導電型クラッド層を成長形成する工程
と、前記第２導電型光導波路層をエッチングしないエッ
チャントを用いて前記第２導電型クラッド層の一部のみ
をエッチングして除去し、前記第２導電型光導波路層上
に光導波路方向に長手方向を有するストライプ状リッジ
を形成する工程と、前記第２導電型光導波路層上の前記
第２導電型クラッド層を除去した部分に第１導電型電流
阻止層を成長形成する工程と、前記第２導電型クラッド
層の残部及び前記第１導電型電流阻止層の上に第２導電
型コンタクト層を成長形成する工程とを含むことを特徴
とする半導体レ−ザ装置の製造方法。3. A step of growing a first conductivity type cladding layer, a non-doped active layer, and a second conductivity type optical waveguide layer on a first conductivity type substrate; a step of forming a distributed feedback section, and growing a second conductivity type cladding layer having a heterogeneous mixed crystal different from the second conductivity type optical waveguide layer on the second conductivity type optical waveguide layer in which the distributed feedback section is formed; forming an optical waveguide on the second conductive type optical waveguide layer, etching and removing only a part of the second conductive type cladding layer using an etchant that does not etch the second conductive type optical waveguide layer; forming a striped ridge having a longitudinal direction; and growing a first conductivity type current blocking layer on a portion of the second conductivity type optical waveguide layer from which the second conductivity type cladding layer has been removed. . A method of manufacturing a semiconductor laser device, comprising the steps of: growing a second conductivity type contact layer on the remainder of the second conductivity type cladding layer and on the first conductivity type current blocking layer.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1702891A JPH04243183A (en) | 1991-01-17 | 1991-01-17 | Semiconductor laser and manufacture thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1702891A JPH04243183A (en) | 1991-01-17 | 1991-01-17 | Semiconductor laser and manufacture thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH04243183A true JPH04243183A (en) | 1992-08-31 |
Family
ID=11932544
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1702891A Pending JPH04243183A (en) | 1991-01-17 | 1991-01-17 | Semiconductor laser and manufacture thereof |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH04243183A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5598290A (en) * | 1993-06-30 | 1997-01-28 | Sharp Kabushiki Kaisha | Data transfer apparatus utilizing infrared rays |
| JP2006269568A (en) * | 2005-03-23 | 2006-10-05 | Fuji Photo Film Co Ltd | Semiconductor laser element |
-
1991
- 1991-01-17 JP JP1702891A patent/JPH04243183A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5598290A (en) * | 1993-06-30 | 1997-01-28 | Sharp Kabushiki Kaisha | Data transfer apparatus utilizing infrared rays |
| JP2006269568A (en) * | 2005-03-23 | 2006-10-05 | Fuji Photo Film Co Ltd | Semiconductor laser element |
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