JP2966494B2 - Visible light semiconductor laser - Google Patents
Visible light semiconductor laserInfo
- Publication number
- JP2966494B2 JP2966494B2 JP2229608A JP22960890A JP2966494B2 JP 2966494 B2 JP2966494 B2 JP 2966494B2 JP 2229608 A JP2229608 A JP 2229608A JP 22960890 A JP22960890 A JP 22960890A JP 2966494 B2 JP2966494 B2 JP 2966494B2
- Authority
- JP
- Japan
- Prior art keywords
- semiconductor laser
- substrate
- visible light
- light semiconductor
- algainp
- 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.)
- Expired - Fee Related
Links
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
- H01S5/00—Semiconductor lasers
- H01S5/30—Structure or shape of the active region; Materials used for the active region
- H01S5/305—Structure or shape of the active region; Materials used for the active region characterised by the doping materials used in the laser structure
- H01S5/3077—Structure or shape of the active region; Materials used for the active region characterised by the doping materials used in the laser structure plane dependent doping
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
- H01S5/00—Semiconductor lasers
- H01S5/30—Structure or shape of the active region; Materials used for the active region
- H01S5/32—Structure or shape of the active region; Materials used for the active region comprising PN junctions, e.g. hetero- or double- heterostructures
- H01S5/3202—Structure or shape of the active region; Materials used for the active region comprising PN junctions, e.g. hetero- or double- heterostructures grown on specifically orientated substrates, or using orientation dependent growth
Landscapes
- Physics & Mathematics (AREA)
- Condensed Matter Physics & Semiconductors (AREA)
- General Physics & Mathematics (AREA)
- Electromagnetism (AREA)
- Optics & Photonics (AREA)
- Semiconductor Lasers (AREA)
Description
【発明の詳細な説明】 （イ）産業上の利用分野 本発明は、AlGaInP系の可視光半導体レーザに関す
る。The present invention relates to an AlGaInP-based visible light semiconductor laser.
（ロ）従来の技術 AlGaInP系化合物半導体は0.6μｍ帯の波長を有し、可
視光半導体レーザの材料として用いられている。(B) Conventional technology AlGaInP-based compound semiconductors have a wavelength in the 0.6 μm band and are used as materials for visible light semiconductor lasers.
第３図は斯るAlGaInP系半導体レーザを示し、例えば
昭和63年秋季応用物理学会予稿集,4p−ZC−11,836頁に
開示されている。FIG. 3 shows such an AlGaInP-based semiconductor laser, which is disclosed, for example, in the Proceedings of the Japan Society of Applied Physics Autumn 1988, 4p-ZC-11, page 836.
図において、（１）はｎ型GaAsからなる基板、（２）
はｎ型（Al0.7Ga0.3）0.5In0.5Ｐからなるｎ型クラッド
層、（３）はアンドープのGa0.5In0.5Ｐからなる活性
層、（４）はｐ型（Al0.7Ga0.3）0.5In0.5Ｐからなるｐ
型クラッド層である。これらの層は周知のMOCVD法、MBE
法等を用いて基板（１）の一主面（1a）上に順次エピタ
キシャル成長される。また、ｐ型クラッド層（４）には
選択的なウェットエッチングにより５μｍの頂部（5a）
幅を有するリッジ（５）が形成されている。In the figure, (1) is a substrate made of n-type GaAs, (2)
Is an n-type cladding layer made of n-type (Al 0.7 Ga 0.3 ) 0.5 In 0.5 P, (3) is an active layer made of undoped Ga 0.5 In 0.5 P, and (4) is a p-type (Al 0.7 Ga 0.3 ) 0.5 In P consisting of 0.5 P
Mold cladding layer. These layers are formed by the well-known MOCVD method, MBE
The epitaxial growth is sequentially performed on one main surface (1a) of the substrate (1) using a method or the like. The p-type cladding layer (4) has a 5 μm top (5a) by selective wet etching.
A ridge (5) having a width is formed.
（６）はｐ型クラッド層（４）上にエピタキシャル成
長されたｎ型GaAsからなるブロック層で、リフトオフ技
術を用いてリッジ（５）の頂部（5a）のブロック層
（６）は除去されている。（７）は露出したｐ型クラッ
ド層（４）上及びブロック層（６）上にエピタキシャル
成長されたｐ型GaAsからなるキャップ層である。(6) is a block layer made of n-type GaAs epitaxially grown on the p-type cladding layer (4). The block layer (6) on the top (5a) of the ridge (5) is removed by using a lift-off technique. . (7) is a cap layer made of p-type GaAs epitaxially grown on the exposed p-type cladding layer (4) and the block layer (6).
（８）はキャップ層（７）上に形成されたｐ側電極、
（９）は基板（１）の他主面（1b）上に形成されたｎ側
電極である。(8) is a p-side electrode formed on the cap layer (7),
(9) is an n-side electrode formed on the other main surface (1b) of the substrate (1).
一方、光ディスク用ピックアップの光源として半導体
レーザが多く用いられている。斯る半導体レーザとし
て、より短波長のものを用いると、光学系によりレーザ
ビームを小さく絞ることができるため、光ディスクの高
密度化が図れる。On the other hand, semiconductor lasers are often used as light sources for optical disk pickups. If a semiconductor laser having a shorter wavelength is used as the semiconductor laser, the laser beam can be narrowed down by the optical system, and the density of the optical disk can be increased.
従って、AlGaInP系の半導体レーザにおいても更なる
短波長化が要望されており、本出願人は、特開平１−68
784号、特願平１−83107号で、GaAs（100）面から〈01
1〉方向にオフした面を結晶成長面に用いることによっ
て更なる短波長化が図れることを提案した。Accordingly, there is a demand for further shortening of the wavelength of AlGaInP-based semiconductor lasers.
No. 784 and Japanese Patent Application No. 1-83107, the <01
It has been proposed that the wavelength can be further shortened by using the plane turned off in the 1> direction as the crystal growth plane.
（ハ）発明が解決しようとする課題 しかし乍ら、このようにGaAs基板をオフさせた場合、
次の問題が生じる。(C) Problems to be solved by the invention However, when the GaAs substrate is turned off in this way,
The following problems arise.
（ｉ）GaAs基板上に形成されるｎ型成長層において、
（100）ジャスト基板を用いた場合に比べ、Ｖ族置換の
ｎ型ドーパントとして用いられるSeのドーピング効率が
低下する。(I) In an n-type growth layer formed on a GaAs substrate,
The doping efficiency of Se used as a group V-substituted n-type dopant is lower than in the case where a (100) just substrate is used.
（ii）ｐ型クラッド層に形成され、通常〈011〉方向に
延在するリッジ（５）の、この方向に垂直な断面の形状
が第４図に示す如く左右非対称となるため、斯るリッジ
形状によって制御される横モードが変化し、レーザ光の
遠視野像が左右非対称となる。(Ii) The ridge (5) formed on the p-type cladding layer and extending normally in the <011> direction has a bilaterally asymmetric cross section perpendicular to this direction as shown in FIG. The lateral mode controlled by the shape changes, and the far-field image of the laser beam becomes left-right asymmetric.
従って、本発明は、オフ基板を用いたことによるAlGa
InP系半導体レーザの短波長化を維持しつつ、ｎ型ドー
パントのドーピング効率が向上し、且つリッジ形状の左
右非対称性が緩和されるAlGaInP系の半導体レーザを提
供するものである。Therefore, the present invention provides an AlGa
It is an object of the present invention to provide an AlGaInP-based semiconductor laser in which the doping efficiency of an n-type dopant is improved and the left-right asymmetry of the ridge shape is reduced while maintaining a shorter wavelength of the InP-based semiconductor laser.
（ニ）課題を解決するための手段 本発明は、GaAs基板上にAlGaInP系の発振層が設けら
れた可視光半導体レーザであって、上記基板の結晶成長
面が（100）面から傾斜した面であると共に、その傾斜
の方向が〈011〉方向から〈01〉方向へα（15゜≦α
≦30゜）ずれた方向であることを特徴とする。(D) Means for Solving the Problems The present invention relates to a visible light semiconductor laser in which an AlGaInP-based oscillation layer is provided on a GaAs substrate, wherein a crystal growth surface of the substrate is inclined from a (100) plane. And the direction of the inclination is α (15 ° ≦ α) from the <011> direction to the <01> direction.
≦ 30 °) The direction is shifted.
（ホ）作用 本発明によれば、基板の結晶成長面が（100）面から
傾斜した面の場合、その傾斜の方向を〈011〉方向から
〈01〉方向へずらすことによって、リッジ形状の左右
非対称性が緩和される。(E) Function According to the present invention, when the crystal growth surface of the substrate is a surface inclined from the (100) plane, the direction of the inclination is shifted from the <011> direction to the <01> direction, so that the right and left sides of the ridge shape are shifted. Asymmetry is reduced.
（ヘ）実施例 本発明は、AlGaInP系化合物半導体のバンドギャップ
がGaAs基板の面方位に依存し、結晶成長面を（100）面
から〈011〉方向に傾斜した面とすることによって、AlG
aInP系半導体レーザの短波長化が図れるといった、本出
願人によって初めて見出された現象を基礎とするもので
ある。(F) Embodiment The present invention provides an AlGaInP-based compound semiconductor in which the band gap depends on the plane orientation of the GaAs substrate, and the crystal growth plane is inclined from the (100) plane in the <011> direction.
This is based on a phenomenon first discovered by the present applicant, such as shortening the wavelength of an aInP-based semiconductor laser.
先ず、GaAs基板の結晶成長面を（100）面から７゜傾
斜させた面とすると共に、その傾斜方向を〈011〉方向
から〈01〉方向までの範囲で種々変えた基板を作製
し、これらの基板の結晶成長面上にGaInP層をMOCVD法を
用いて成長させ、これらの成長層のバンドギャップの変
化を測定した。その結果を第１図に示す。ここで、第１
図では、横軸を傾斜方向と〈011〉軸とのなす角α（０
≦α≦90゜）とし、縦軸をGaAs基板の（100）面上に成
長したGaInP層のバンドギャップを基準とした、夫々の
バンドギャップのシフト量としている。また、各成長層
の成長条件は、成長温度を620℃、原料ガスのV/III供給
比を550とした。First, a GaAs substrate was prepared with a crystal growth plane inclined by 7 ° from the (100) plane, and the inclination direction was varied in a range from the <011> direction to the <01> direction. A GaInP layer was grown on the crystal growth surface of the substrate by MOCVD, and the change in band gap of these growth layers was measured. The result is shown in FIG. Here, the first
In the figure, the horizontal axis represents the angle α (0) between the tilt direction and the <011> axis.
.Ltoreq..alpha..ltoreq.90.degree.), And the vertical axis indicates the shift amount of each band gap with respect to the band gap of the GaInP layer grown on the (100) plane of the GaAs substrate. The growth conditions for each growth layer were such that the growth temperature was 620 ° C., and the V / III supply ratio of the source gas was 550.
図より、なす角αが大きくなる程バンドギャップが小
さくなっていくものの、０＜α≦30゜の範囲であれば、
その変化量は小さく、バンドギャップは、α＝０のと
き、即ち傾斜方向を〈011〉方向とした場合とほとんど
変わらないことが分かる。As shown in the figure, the band gap becomes smaller as the angle α becomes larger, but in the range of 0 <α ≦ 30 °,
It can be seen that the change amount is small, and the band gap is almost the same as when α = 0, that is, when the inclination direction is the <011> direction.
また、斯る特性は、基板の傾斜方向が結晶学的に等価
な方向、即ち、〈011〉方向から〈０１〉方向へずら
した場合、〈０〉方向から〈01〉方向へずらした
場合、〈０〉方向から〈０１〉方向へずらした場
合おいても同様に生じる。従って、本発明で示す結晶方
位は、結晶学的に等価な方位を含むものである。Further, such a characteristic is that the tilt direction of the substrate is crystallographically equivalent direction, that is, when the substrate is shifted from the <011> direction to the <01> direction, when the substrate is shifted from the <0> direction to the <01> direction, The same occurs when the direction is shifted from the <0> direction to the <01> direction. Therefore, the crystal orientation described in the present invention includes a crystallographically equivalent orientation.
次に、αを夫々０゜,15゜,30゜として第３図と同構造
の半導体レーザを作製し、発振波長、ｎ型ドーパントの
ドーピング効率、リッジの非対称性（第４図における|a
−b|）、及び最高発振温度について調べた。その結果を
表１に示す。ここで、ｎ型ドーパントのドーピング効率
は、ｎ型ドーパントをSe（ドーパントガス:H2Se）とし
たときのｎ型クラッド層（２）における効率を示し、α
＝０のときのドーパント効率を１とした相対値である。Next, a semiconductor laser having the same structure as that shown in FIG. 3 was manufactured by setting α to 0 °, 15 °, and 30 °, respectively, and the oscillation wavelength, the doping efficiency of the n-type dopant, and the ridge asymmetry (| a in FIG. 4)
−b |), and the maximum oscillation temperature. Table 1 shows the results. Here, the doping efficiency of the n-type dopant indicates the efficiency in the n-type cladding layer (2) when the n-type dopant is Se (dopant gas: H 2 Se), and α
This is a relative value when the dopant efficiency when = 0 is 1.
表１より、α＝15,30゜とした半導体レーザでは、い
ずれもα＝０とした半導体レーザと略同等の発振波長が
得られていると共に、リッジの非対称性が緩和され、ｎ
型ドーパントのドーピング効率が高くなっていることが
分かる。また、α＝15,30゜では、α＝０に比べ最高発
振温度が高くなっていることから、高温における半導体
レーザの出力特性が向上していることが分かる。 From Table 1, it can be seen from Table 1 that in each of the semiconductor lasers with α = 15, 30 °, almost the same oscillation wavelength as that of the semiconductor laser with α = 0 is obtained, the asymmetry of the ridge is reduced, and n
It can be seen that the doping efficiency of the type dopant is high. At α = 15, 30 °, the maximum oscillation temperature is higher than at α = 0, indicating that the output characteristics of the semiconductor laser at high temperatures are improved.
更に、α＝０とした半導体レーザとα＝30゜とした半
導体レーザとで、50℃の環境下で5mWの定出力動作によ
る信頼性試験を行った。その結果を第２図に破線（α＝
０）と実線（α＝30゜）にて示す。Further, a reliability test was performed on a semiconductor laser with α = 0 and a semiconductor laser with α = 30 ° by a constant output operation of 5 mW in an environment of 50 ° C. The results are shown in FIG.
0) and a solid line (α = 30 °).
図より、α＝30゜とした半導体レーザのほうがα＝０
とした半導体レーザよりも劣化が少なく、信頼性が高い
ことが分かる。これは、基板の傾斜方向を〈011〉方向
から〈01〉方向へずらすことによって、GaAs基板上に
形成されるAlGaInP層、GaInP結晶の結晶性が向上したも
のと考えられる。即ち、基板の傾斜方向を〈011〉方向
から〈01〉方向へずらすことは、リッジの非対称性を
緩和するだけではなく、AlGaInP系結晶の結晶性の向上
にも効果があるものである。From the figure, it is clear that the semiconductor laser with α = 30 ° has α = 0
It can be seen that the semiconductor laser is less deteriorated and has higher reliability than the semiconductor laser described above. This is presumably because the crystallinity of the AlGaInP layer and the GaInP crystal formed on the GaAs substrate was improved by shifting the tilt direction of the substrate from the <011> direction to the <01> direction. That is, shifting the tilt direction of the substrate from the <011> direction to the <01> direction not only reduces the asymmetry of the ridge, but also has an effect on improving the crystallinity of the AlGaInP-based crystal.
以上本実施例では、基板の傾斜角を７゜としたが、５
゜以上であれば半導体レーザの短波長化が図れ、本実施
例と同じく、０＜α≦30゜の範囲で同様の効果が得られ
る。As described above, in the present embodiment, the inclination angle of the substrate is set to 7 °.
If it is not less than ゜, the wavelength of the semiconductor laser can be shortened, and the same effect can be obtained in the range of 0 <α ≦ 30 ° as in this embodiment.
（ト）発明の効果 本発明によれば、（100）面から傾斜した結晶成長面
を有する基板の傾斜方向を〈011〉方向から〈01〉方
向へα（15゜≦α≦30゜）ずれた方向とすることによっ
て、リッジ形状の左右非対称性が緩和されると共に、成
長層の結晶性が向上するため、ｎ型ドーパントのドーピ
ング効率、最高発振温度の向上が図れる。(G) Effects of the Invention According to the present invention, the inclination direction of a substrate having a crystal growth surface inclined from the (100) plane is shifted from the <011> direction to the <01> direction by α (15 ° ≦ α ≦ 30 °). By adjusting the direction, the left-right asymmetry of the ridge shape is reduced and the crystallinity of the growth layer is improved, so that the doping efficiency of the n-type dopant and the maximum oscillation temperature can be improved.
第１図は基板の傾斜方向に対するGaInP結晶のバンドギ
ャップの変化を示す特性図、第２図は本実施例装置の信
頼性試験結果を示す特性図、第３図はAlGaInP系半導体
レーザの構造を示す断面図、第４図は基板を傾斜させた
ときのリッジ形状を示す要部拡大図である。FIG. 1 is a characteristic diagram showing a change in a band gap of a GaInP crystal with respect to a tilt direction of a substrate, FIG. 2 is a characteristic diagram showing a reliability test result of the device of the present embodiment, and FIG. 3 is a diagram showing a structure of an AlGaInP-based semiconductor laser. FIG. 4 is an enlarged view of a main part showing a ridge shape when the substrate is inclined.
───────────────────────────────────────────────────── フロントページの続き (72)発明者 廣山 良治 大阪府守口市京阪本通２丁目18番地 三 洋電機株式会社内 (56)参考文献 特開 平３−198391（ＪＰ，Ａ) 特開 平４−37081（ＪＰ，Ａ) 特開 平４−35080（ＪＰ，Ａ) 電子情報通信学会技術研究報告89 ［284］ＥＤ89−106（1989）Ｐ．57−64 (58)調査した分野(Int.Cl.6，ＤＢ名) H01S 3/18 ──────────────────────────────────────────────────続 き Continuation of front page (72) Inventor Ryoji Hiroyama 2-18-18 Keihanhondori, Moriguchi-shi, Osaka Sanyo Electric Co., Ltd. (56) References JP-A-3-198391 (JP, A) JP-A-Hei JP-A-4-37081 (JP, A) JP-A-4-35080 (JP, A) IEICE technical report 89 [284] ED89-106 (1989) 57-64 (58) Field surveyed (Int. Cl. 6 , DB name) H01S 3/18
Claims (1)
れた可視光半導体レーザにおいて、上記基板の結晶成長
面が（100）面から傾斜した面であると共に、その傾斜
の方向が＜011＞方向から＜01＞方向へα（15゜≦α
≦30゜）ずれた方向であることを特徴とする可視光半導
体レーザ。In a visible light semiconductor laser having an AlGaInP-based oscillation layer provided on a GaAs substrate, the crystal growth surface of the substrate is inclined from the (100) plane, and the inclination direction is <011. Α from the direction to the <01> direction (15 ゜ ≦ α
≦ 30 °) A visible light semiconductor laser characterized in that the directions are shifted.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2229608A JP2966494B2 (en) | 1990-08-30 | 1990-08-30 | Visible light semiconductor laser |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2229608A JP2966494B2 (en) | 1990-08-30 | 1990-08-30 | Visible light semiconductor laser |
Related Child Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP12044199A Division JPH11340583A (en) | 1999-04-27 | 1999-04-27 | Manufacture of visible light semiconductor laser |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH04111379A JPH04111379A (en) | 1992-04-13 |
| JP2966494B2 true JP2966494B2 (en) | 1999-10-25 |
Family
ID=16894845
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2229608A Expired - Fee Related JP2966494B2 (en) | 1990-08-30 | 1990-08-30 | Visible light semiconductor laser |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2966494B2 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7465353B2 (en) | 2004-09-17 | 2008-12-16 | Nippon Mining & Metals Co., Ltd. | Method for growing epitaxial crystal |
-
1990
- 1990-08-30 JP JP2229608A patent/JP2966494B2/en not_active Expired - Fee Related
Non-Patent Citations (1)
| Title |
|---|
| 電子情報通信学会技術研究報告８９［２８４］ＥＤ８９−１０６（１９８９）Ｐ．５７−６４ |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH04111379A (en) | 1992-04-13 |
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