JPS6244718B2 - - Google Patents
Info
- Publication number
- JPS6244718B2 JPS6244718B2 JP15533980A JP15533980A JPS6244718B2 JP S6244718 B2 JPS6244718 B2 JP S6244718B2 JP 15533980 A JP15533980 A JP 15533980A JP 15533980 A JP15533980 A JP 15533980A JP S6244718 B2 JPS6244718 B2 JP S6244718B2
- Authority
- JP
- Japan
- Prior art keywords
- light emitting
- light
- type
- region
- active 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.)
- Expired
Links
- 238000000034 method Methods 0.000 description 20
- 238000005253 cladding Methods 0.000 description 11
- 230000003287 optical effect Effects 0.000 description 11
- 239000013307 optical fiber Substances 0.000 description 11
- 238000009792 diffusion process Methods 0.000 description 10
- 239000010408 film Substances 0.000 description 10
- 239000013078 crystal Substances 0.000 description 9
- 229910004298 SiO 2 Inorganic materials 0.000 description 6
- 239000002184 metal Substances 0.000 description 6
- 229910052751 metal Inorganic materials 0.000 description 6
- 239000000758 substrate Substances 0.000 description 6
- 229910001218 Gallium arsenide Inorganic materials 0.000 description 4
- 238000003486 chemical etching Methods 0.000 description 4
- 238000000992 sputter etching Methods 0.000 description 4
- 238000010586 diagram Methods 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 229910000980 Aluminium gallium arsenide Inorganic materials 0.000 description 2
- 229910003460 diamond Inorganic materials 0.000 description 2
- 239000010432 diamond Substances 0.000 description 2
- 238000000605 extraction Methods 0.000 description 2
- 230000031700 light absorption Effects 0.000 description 2
- 239000007791 liquid phase Substances 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 239000004065 semiconductor Substances 0.000 description 2
- 238000004544 sputter deposition Methods 0.000 description 2
- 239000010409 thin film Substances 0.000 description 2
- 238000001947 vapour-phase growth Methods 0.000 description 2
- 229910018072 Al 2 O 3 Inorganic materials 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 229910052793 cadmium Inorganic materials 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 239000000284 extract Substances 0.000 description 1
- 239000000835 fiber Substances 0.000 description 1
- 230000020169 heat generation Effects 0.000 description 1
- 238000002347 injection Methods 0.000 description 1
- 239000007924 injection Substances 0.000 description 1
- 230000010355 oscillation Effects 0.000 description 1
- 238000007747 plating Methods 0.000 description 1
- 230000001902 propagating effect Effects 0.000 description 1
- 230000005855 radiation Effects 0.000 description 1
- 229910052725 zinc Inorganic materials 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L33/00—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
- H01L33/02—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by the semiconductor bodies
- H01L33/16—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by the semiconductor bodies with a particular crystal structure or orientation, e.g. polycrystalline, amorphous or porous
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L33/00—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
- H01L33/02—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by the semiconductor bodies
- H01L33/20—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by the semiconductor bodies with a particular shape, e.g. curved or truncated substrate
Landscapes
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Computer Hardware Design (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Power Engineering (AREA)
- Led Device Packages (AREA)
- Led Devices (AREA)
Description
【発明の詳細な説明】
本発明は光フアイバー通信用を主目的とした発
光ダイオードに関する。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a light emitting diode primarily intended for use in optical fiber communications.
光フアイバー通信用発光ダイオードの最大の課
題は、輝度を高くする事、発光面積を小さくする
事、及び光の取り出し効率を上げる事の三点にあ
る。これ迄、面発光型と端面発光型の発光ダイオ
ードが実現されている。面発光型発光ダイオード
では小さな発光面積で高い輝度を得るために、
10kA／cm2前後の高密度の電流が流される。この
ため、発光領域の発熱に伴う光出力の飽和が生じ
易く、信頼性上の問題が生じ易いという欠点をも
つている。 The three biggest challenges for light-emitting diodes for fiber optic communications are increasing brightness, reducing light emitting area, and increasing light extraction efficiency. Up to now, surface-emitting type and edge-emitting type light emitting diodes have been realized. In surface-emitting light emitting diodes, in order to obtain high brightness with a small light emitting area,
A high-density current of around 10 kA/cm 2 is applied. Therefore, saturation of the light output due to heat generation in the light emitting region is likely to occur, and reliability problems are likely to occur.
一方、端面発光型発光ダイオードでは、低電流
密度で高い輝度が得られるが、光が活性層内部で
吸収されるために光出力が小さく、非線型性も大
きいという欠点をもつている。 On the other hand, edge-emitting light emitting diodes can provide high brightness at low current density, but have the drawbacks of low light output and large nonlinearity because light is absorbed within the active layer.
本発明の目的は実効発光面積が小さく、高輝
度、高出力、高線型性の発光ダイオードを得る事
にある。 An object of the present invention is to obtain a light emitting diode with a small effective light emitting area, high brightness, high output, and high linearity.
本発明によれば、細長いストライプ発光領域に
直交し、且つ活性層に対して傾斜角を有する光放
射面をもつ事を特徴とする発光ダイオードが得ら
れる。 According to the present invention, a light emitting diode is obtained which is characterized by having a light emitting surface that is perpendicular to the elongated striped light emitting region and has an inclined angle with respect to the active layer.
本発明の原理は、面発光型と端面発光型発光ダ
イオードの両長所を結合し、且つ、発光領域を斜
めにみる事によつて、光学的に発光領域を小さく
する事にある。光フアイバーに発光ダイオードか
らの光を入れる場合、発光領域の小さい事が望ま
しい。活性層に垂直に光を取り出す面発光型発光
ダイオードでは、コア径50μｍφの光フアイバー
に適用した場合、発光径は30μｍφ前後が望まし
い。光出力を大きくするには電流を増すが、容易
に10KA／cm2程度の高電流密度に達する。このた
め、発光領域の温度上昇による光出力の飽和及び
信頼性上の諸問題が発生する。もし、発光径30μ
ｍφ相当の発光領域から、小電流密度で大きな光
出力が得られれば、これらの問題は解消し、大光
出力、高信頼性、高線型性の発光ダイオードが出
現する。細長いストライプ発光領域を有し、活性
層に平行方向に光を取り出す端面発光型発光ダイ
オードでは、反射面からみた発光領域は（ストラ
イプ巾（10〜20μｍ）×（活性層厚（〜１μｍ））
と小さい。ストライプ発光領域が大きく、光の取
り出し口である反射面上の発光領域が小さいた
め、低電流密度で高い輝度の光が得られる。
AlGaAs、GaAs、InGaAsP、AlGaAsSb、InP等
の発光ダイオード用結晶の屈折率はほぼ3.5と大
きいため、空中へ放射されるための反射面に対す
る入射臨界角は約16度と小さい。その上、光フア
イバーの開口数は小さい（NA〓0.2）から、光フ
アイバーに入る光の殆んどは、活性層に平行な、
即ち、活性層内を伝播する光から成つている。活
性層内を伝播する過程で、高光エネルギー成分の
光は吸収されるから、大きな光出力は得られな
い。これが端面発光型発光ダイオードの面発光型
発光ダイオードに比べて劣る点である。また、誘
導放出光成分が大きいために、電流―光出力特性
の線型性が悪い。従つて、端面発光型に於いて、
面発光型のように光吸収及び誘導放出成分がない
状態で外部に光を取り出す事ができれば、高輝
度、高出力、高線型性、低電流密度という現想の
状態が実現する。これを成すためには、端面発光
型に於いて、活性層に垂直な反射面を活性層に対
して傾斜角をもつた光放射面変更すればよい。 The principle of the present invention is to combine the advantages of both surface-emitting type and edge-emitting type light-emitting diodes, and to optically reduce the light-emitting area by viewing the light-emitting area obliquely. When introducing light from a light emitting diode into an optical fiber, it is desirable that the light emitting area be small. In a surface emitting type light emitting diode that extracts light perpendicularly to the active layer, when applied to an optical fiber with a core diameter of 50 μmφ, the emission diameter is preferably around 30 μmφ. To increase the optical output, the current is increased, and a high current density of about 10 KA/cm 2 is easily reached. For this reason, saturation of light output and reliability problems occur due to temperature rise in the light emitting region. If the emission diameter is 30μ
If a large light output can be obtained with a small current density from a light emitting region equivalent to mφ, these problems will be solved, and a light emitting diode with a large light output, high reliability, and high linearity will appear. In an edge-emitting type light emitting diode that has an elongated striped light emitting region and takes out light in a direction parallel to the active layer, the light emitting region seen from the reflective surface is (stripe width (10-20 μm) x (active layer thickness (~1 μm))
And small. Since the stripe light emitting area is large and the light emitting area on the reflective surface, which is the light extraction port, is small, high brightness light can be obtained with low current density.
Since the refractive index of crystals for light emitting diodes such as AlGaAs, GaAs, InGaAsP, AlGaAsSb, and InP is as large as approximately 3.5, the critical angle of incidence with respect to the reflecting surface for radiation into the air is as small as approximately 16 degrees. Moreover, since the numerical aperture of the optical fiber is small (NA〓0.2), most of the light entering the optical fiber is parallel to the active layer.
That is, it consists of light propagating within the active layer. During the process of propagation within the active layer, high optical energy components of light are absorbed, so a large optical output cannot be obtained. This is a point in which edge-emitting type light emitting diodes are inferior to surface-emitting type light emitting diodes. Furthermore, since the stimulated emission light component is large, the linearity of the current-light output characteristic is poor. Therefore, in the edge-emitting type,
If it is possible to extract light to the outside without light absorption and stimulated emission components like in a surface-emitting type, the current state of high brightness, high output, high linearity, and low current density can be realized. In order to accomplish this, in the edge-emitting type, the reflecting surface perpendicular to the active layer may be changed to a light emitting surface having an inclination angle with respect to the active layer.
第１図に本発明の原理図が示されている。傾角
θをもつた光放射面１００にほぼ垂直に活性層１
０１のストライプ発光領域１０２から放射された
光１０５が、光フアイバーに有効に結合される。
勿論、光の通過する領域１０３はストライプ発光
領域１０２から出る光に対して透明でなければな
らない。この条件は光通過領域１０３がダブルヘ
テロ構造のクラツド層であれば満足されている。
光放射面１００が活性層１０１に対して角度θを
もつているために、ストライプ発光領域１０２の
光放射面１００上の光源像１０４は長さ方向に対
してcosθだけ縮小される。即ち、ストライプ発
光領域１１の長さをＬ、ストライプ巾をＳとすれ
ば、光放射面１００上の光源像１０４の大きさは
Lcosθ×Ｓとなる。Lcosθ・sinθが光通過領域
１０４の厚さより小さければ、光は有効に外部に
放射される。一例として、Ｌ＝200μｍ、θ＝80
゜、Ｓ＝20μｍとすれば光源像１０４の大きさは
35μｍ×20μｍとなる。また、光放射面が傾斜し
ているため、レーザ発振を抑止できる。傾斜角θ
をもつ光放射面１００は化学エツチング法、イオ
ンミリング法及びイオンミリング法＋化学エツチ
ング法等多くの方法で実現できる。本発明は結晶
材料に依存しない発光ダイオードの本質的な構造
を提供する。 FIG. 1 shows a diagram of the principle of the present invention. The active layer 1 is arranged almost perpendicularly to the light emitting surface 100 having an inclination angle θ.
Light 105 emitted from the stripe light emitting region 102 of 01 is effectively coupled to the optical fiber.
Of course, the light passing region 103 must be transparent to the light emitted from the striped light emitting region 102. This condition is satisfied if the light passing region 103 is a double heterostructure cladding layer.
Since the light emitting surface 100 has an angle θ with respect to the active layer 101, the light source image 104 on the light emitting surface 100 of the striped light emitting region 102 is reduced by cos θ in the length direction. That is, if the length of the striped light emitting region 11 is L and the stripe width is S, then the size of the light source image 104 on the light emitting surface 100 is
It becomes Lcosθ×S. If L cos θ·sin θ is smaller than the thickness of the light passing region 104, the light is effectively radiated to the outside. As an example, L=200μm, θ=80
゜, S = 20 μm, the size of the light source image 104 is
The size is 35μm×20μm. Furthermore, since the light emitting surface is inclined, laser oscillation can be suppressed. Inclination angle θ
The light emitting surface 100 having the above-mentioned structure can be realized by many methods such as chemical etching method, ion milling method, and ion milling method + chemical etching method. The present invention provides an essential structure of a light emitting diode that is independent of the crystal material.
次に本発明について図面を参照し乍ら説明す
る。 Next, the present invention will be explained with reference to the drawings.
第２図は波長1.3μｍの光を出すInGaAsP／InP
ダブルヘテロ構造発光ダイオードに本発明を適用
した典型例を示す。厚さ80μｍのｎ型InP基板２
００上に、よく知られた液相成長法又は気相成長
法で、厚さ３μｍのｎ形InPクラツド層２０１、
厚さ１μｍのｐ形（又はｎ形）InGaAsP（波長
1.3μｍ）活性層２０２、厚さ２μｍのｐ形InPク
ラツド層２０３及び厚さ１μｍのｐ形InGaAsP
（波長1.1μｍ）キヤツプ層２０４が設けられてい
る。キヤツプ層２０４上にCVD又はスパツタ法
で設けられたSiO2膜２０５は、巾20μｍの細長
いストライプ状領域だけ除去されており、この領
域にはキヤツプ層２０４又はクラツド層２０３に
達するZn又はCdのp+拡散領域２０６が設けられ
ている。p+拡散領域２０６及びSiO2膜２０５上
にはAu−Znのｐ形オーミツク電極及びヒートシ
ンクへの接着用Au層２０７が設けられている。
ｎ形InP基板２００上にはAu−Ge−Niのｎ形オ
ーミツク電極及びリード線がボンデイング用Au
層２０８が設けられている。ｐ形オーミツク電極
側金属２０７はダイヤモンドヒートシンク２０９
にSnで融着されている。光放射面２１０はスト
ライプ状のp+拡散領域２０６に直交し、且つ活
性層２０２と約85゜の角度をなす鏡面である。ｐ
形オーミツク電極２０７に（＋）、ｎ形オーミツ
ク電極２０８に（−）の電圧をかけて順方向電流
を流すと、結晶の長さ方向200μｍの全域に亘つ
てのびているストライプ状のp+拡散領域２０６
直下の活性層（ストライプ発光領域）２１１が、
半導体レーザの場合と同様、発光する。光放射面
２１０の垂線方向を中心にランバーシアン分布を
もつて光２１３は空中に放射される。従つて、光
放射面２１０上に生ずる発光領域像（光源像）２
１２の大きさは約20μｍ×20μｍとなる。 Figure 2 shows InGaAsP/InP that emits light with a wavelength of 1.3 μm.
A typical example in which the present invention is applied to a double heterostructure light emitting diode is shown. 80μm thick n-type InP substrate 2
00, an n-type InP cladding layer 201 with a thickness of 3 μm is formed using a well-known liquid phase growth method or vapor phase growth method.
1 μm thick p-type (or n-type) InGaAsP (wavelength
1.3 μm) active layer 202, 2 μm thick p-type InP cladding layer 203, and 1 μm thick p-type InGaAsP
(Wavelength: 1.1 μm) A cap layer 204 is provided. The SiO 2 film 205 provided on the cap layer 204 by CVD or sputtering is removed only in an elongated striped region with a width of 20 μm, and in this region there is no Zn or Cd plating layer that reaches the cap layer 204 or the cladding layer 203. + A diffusion region 206 is provided. On the p + diffusion region 206 and the SiO 2 film 205, an Au--Zn p-type ohmic electrode and an Au layer 207 for adhesion to a heat sink are provided.
On the n-type InP substrate 200, Au-Ge-Ni n-type ohmic electrodes and lead wires are connected to Au for bonding.
A layer 208 is provided. The metal 207 on the p-type ohmic electrode side is a diamond heat sink 209
is fused with Sn. The light emitting surface 210 is a mirror surface that is perpendicular to the striped p + diffusion region 206 and forms an angle of approximately 85° with the active layer 202 . p
When a (+) voltage is applied to the ohmic electrode 207 and a (-) voltage is applied to the n-type ohmic electrode 208 and a forward current is caused to flow, a stripe-shaped p + diffusion region extending over the entire 200 μm length direction of the crystal is formed. 206
The active layer (stripe light emitting region) 211 directly below is
As in the case of a semiconductor laser, it emits light. The light 213 is emitted into the air with a Lambertian distribution centered on the perpendicular direction of the light emitting surface 210. Therefore, the light emitting area image (light source image) 2 generated on the light emitting surface 210
The size of 12 is approximately 20 μm×20 μm.
100ｍＡを流した時の典型的な光出力は約３ｍ
Ｗであり、コア径50μｍ、NA＝0.2の傾斜型屈折
率分布をもつ光フアイバーに入る光出力は、通常
のレンズを用いて、約150ｍＷである。光放射面
２１０と活性層２０２のなす角θが90度の通常の
端面発光型発光ダイオードでは、光源像は約１μ
ｍ×20μｍと小さい。この場合には活性層内の光
吸収が大きく、100ｍＡ流した時の典型的な光出
力は約0.5ｍＷであり、同じ光フアイバーに入る
光出力は約25μｍＷである。面発光型発光ダイオ
ードでは、100ｍＡの電流を流して約３ｍＷの光
出力が得られるが、200μｍ長の光学像では大き
すぎて、長さ約40μｍのストライプ発光領域の発
光しか光フアイバーに入らない。このため、光フ
アイバーに入る光出力は約30μｍＷである。一
方、発光領域を20μｍ×20μｍの小さな矩形にし
て100ｍＡを流した場合には、発光領域に流れる
電流密度は約10倍になる。InGaAsP／InPダブル
ヘテロ構造では、電流密度、即ち、注入キヤリヤ
ー密度が大きくなると、光出力が本質的に増加し
にくくなる。このため、この場合には、100ｍＡ
の電流で約１ｍＷの光出力になり、光フアイバー
に入る光出力も約50μｍＷとなる。 Typical light output at 100mA is approximately 3m
The optical power entering an optical fiber having a gradient refractive index distribution with a core diameter of 50 μm and NA=0.2 is approximately 150 mW using a normal lens. In a normal edge-emitting light emitting diode in which the angle θ between the light emitting surface 210 and the active layer 202 is 90 degrees, the light source image is approximately 1μ.
Small, m x 20 μm. In this case, the light absorption within the active layer is large, with a typical light output of about 0.5 mW at 100 mA, and a light output of about 25 μmW entering the same optical fiber. A surface-emitting type light emitting diode can produce a light output of about 3 mW by passing a current of 100 mA, but an optical image with a length of 200 μm is too large, and only light emitted from a stripe light-emitting region with a length of about 40 μm enters the optical fiber. Therefore, the optical power entering the optical fiber is approximately 30 μmW. On the other hand, if the light emitting region is a small rectangle of 20 μm x 20 μm and 100 mA is applied, the current density flowing through the light emitting region will be approximately 10 times greater. In the InGaAsP/InP double heterostructure, the optical output becomes inherently difficult to increase as the current density, ie, the injection carrier density, increases. Therefore, in this case, 100mA
With a current of , the optical output is about 1 mW, and the optical output entering the optical fiber is also about 50 μmW.
ところで、ｐ形オーミツク電極２０７とキヤツ
プ層２０４との境界が光の反射率の高い状態で作
られている時は、本発明の効果は更に大きくな
る。等方的に放射される自然放出光の内、ｐ形オ
ーミツク電極２０７側に放射される光は、反射さ
れて、光放出面２１０に向かうから、反射率が
100％であれば、上記の値のほぼ２倍の光出力が
得られる。更に光放射面２１０上にSiO2、
Al2O3、Si3N4等の誘電体薄膜による反射防止膜を
施せば、更に光出力を30％増加させる事ができ
る。 By the way, when the boundary between the p-type ohmic electrode 207 and the cap layer 204 is made in a state where the reflectance of light is high, the effects of the present invention are even greater. Of the spontaneously emitted light that is isotropically emitted, the light that is emitted toward the p-type ohmic electrode 207 is reflected and goes toward the light emitting surface 210, so that the reflectance increases.
If it is 100%, the light output will be approximately twice the above value. Furthermore, SiO 2 is placed on the light emitting surface 210.
If an anti-reflection coating is applied using a dielectric thin film such as Al 2 O 3 or Si 3 N 4 , the optical output can be further increased by 30%.
第３図は本発明の実施例を0.8μｍの光を出す
AlGaAsダブルヘテロ構造発光ダイオードに本発
明を適用した他の実施例である。厚さ30μｍのｎ
形GaAs基板３００上に、よく知られた液相成長
法又は気相成長法で、厚さ50μｍのｎ形
Al0.3Ga0.7Asクラツド層３０１、厚さ1.5μｍの
ｐ形（又はｎ形）Al0.05Ga0.95As活性層３０２、
厚さ1.5μｍのｐ形Al0.3Ga0.7Agクラツド層３０
３及びｎ形Al0.15Ga0.85Asキヤツプ層３０４が設
けられている。キヤツプ層３０４上にCVD又は
スパツタ法で設けられたSiO2膜には巾30μｍの
細長いストライプ状領域だけ除去されて、この領
域にはｐ形Al0.3Ga0.7Asクラツド層３０３に達す
るZnのp+拡散領域３０５が設けられている。
SiO2膜が全て除去された後、キヤツプ層３０４
上面にAu／Crのｐ形オーミツク電極３０６が、
ｎ形GaAs基板上にはAu／An−Ge−Niのｎ形オ
ーミツク電極３０７が設けられている。ｐ形オー
ミツク電極３０６はSiヒートシンク３０８にAu
−Snで融着される。光反射面３０９及び光放射
面３１０はストライプ状のp+拡散領域３０５に
直交し、且つ活性層３０２と約80度の角度をなす
鏡面である。順方向電流を流すと結晶の長さ方向
200μｍ全域に亘つてのびているストライプ状の
p+拡散領域３０５直下の活性層（ストライプ発
光領域）３１１が発光する。光放射面３１０上に
生ずる発光領域像（光源像）３１２の大きさは約
35μｍ×30μｍである。この場合、ｐ形オーミツ
ク電極３０６とキヤツプ層３０４との境界３１３
は高い光の反射率が得られるように処理されてい
る。従つて、光反射面３０９に向かつた光はそこ
で反射され、且つ境界３１２で反射されて光放射
面３１０を通つて放射される（光線３１４）。そ
の結果、第２図の場合より大きな光出力が得られ
る。光反射面３０９上には誘電体多層膜又は（誘
電体膜＋金属薄膜）による反射膜を形成し、光放
射面３１０上には無反射膜を形成する事は極めて
望ましい。これにより、第２図の場合の約1.5〜
２倍の改善効果が得られる。その上、活性層が結
晶端に露出しているために生ずる劣化も防止でき
る。このように、本発明によれば、従来の数倍の
高光出力と高線型性が得られる。 Figure 3 shows an embodiment of the present invention that emits light of 0.8 μm.
This is another embodiment in which the present invention is applied to an AlGaAs double heterostructure light emitting diode. 30μm thick n
A 50 μm thick n-type film was grown on a GaAs substrate 300 using a well-known liquid phase growth method or vapor phase growth method.
Al 0.3 Ga 0.7 As cladding layer 301, 1.5 μm thick p-type (or n- type ) Al 0.05 Ga 0.95 As active layer 302,
1.5 μm thick p -type Al 0.3 Ga 0.7 Ag cladding layer 30
3 and n-type Al 0.15 Ga 0.85 As cap layers 304 are provided . The SiO 2 film provided on the cap layer 304 by CVD or sputtering is removed only in an elongated striped region with a width of 30 μm, and this region reaches the p-type Al 0.3 Ga 0.7 As cladding layer 303. A p + diffusion region 305 of Zn is provided.
After all the SiO 2 film is removed, the cap layer 304
An Au/Cr p-type ohmic electrode 306 is on the top surface.
An n-type ohmic electrode 307 of Au/An-Ge-Ni is provided on the n-type GaAs substrate. The p-type ohmic electrode 306 is made of Au on the Si heat sink 308.
-Fused with Sn. The light reflecting surface 309 and the light emitting surface 310 are mirror surfaces that are perpendicular to the striped p + diffusion region 305 and form an angle of about 80 degrees with the active layer 302 . When a forward current is applied, the length direction of the crystal
A striped pattern extending over the entire 200 μm area.
The active layer (stripe light emitting region) 311 directly under the p + diffusion region 305 emits light. The size of the light emitting area image (light source image) 312 generated on the light emitting surface 310 is approximately
It is 35 μm x 30 μm. In this case, the boundary 313 between the p-type ohmic electrode 306 and the cap layer 304
are treated to provide high light reflectance. Therefore, light directed towards the light reflecting surface 309 is reflected there, and is reflected at the boundary 312 and emitted through the light emitting surface 310 (ray 314). As a result, a larger light output can be obtained than in the case of FIG. It is extremely desirable to form a reflective film such as a dielectric multilayer film or (dielectric film+metal thin film) on the light reflecting surface 309, and to form a non-reflective film on the light emitting surface 310. As a result, approximately 1.5~
A double improvement effect can be obtained. Moreover, deterioration caused by the active layer being exposed at the crystal edges can be prevented. As described above, according to the present invention, it is possible to obtain optical output several times higher than that of the conventional method and high linearity.
以上、典型例について説明したが、本発明の実
施例は上記に限る事はない。結晶材料、ｎ形及び
ｐ形の導電型、キヤツプ層の有無、層厚、ストラ
イプ巾、オーミツク電極等任意に選びうる。スト
ライプ領域の形成方法についても、上記の拡散法
の他に、プロトン照射法、選択結晶成長による埋
め込み法等、半導体レーザで使われている全ての
方法を適用することができる。ストライプ領域は
必ずしも結晶端に迄のびている必要はない。最も
重要な光放射面については、その傾斜角は光通過
領域の厚さとストライプ活性領域長とから決まる
許容範囲内では任意である。また、この範囲外で
も程度の差で、本発明の効果は得られる。光放射
面の形成方法については、斜め照射のイオンミリ
ング法、（イオンミリング＋化学エツチング）法
及び逆メサを形成し易い結晶方位を利用したH2
−SO4系、HBr系等による化学エツチング法他多
くの技術を適用する事ができる。 Although typical examples have been described above, the embodiments of the present invention are not limited to the above. The crystal material, n-type and p-type conductivity type, presence or absence of a cap layer, layer thickness, stripe width, ohmic electrode, etc. can be selected arbitrarily. As for the method of forming the stripe region, in addition to the above-mentioned diffusion method, all methods used in semiconductor lasers, such as proton irradiation method and embedding method by selective crystal growth, can be applied. The striped region does not necessarily have to extend to the crystal edge. As for the most important light emitting surface, its inclination angle is arbitrary within the allowable range determined by the thickness of the light passing region and the length of the striped active region. Further, even outside this range, the effects of the present invention can be obtained to varying degrees. Methods for forming the light emitting surface include ion milling method with oblique irradiation, (ion milling + chemical etching) method, and H 2 method using crystal orientation that facilitates the formation of reverse mesas.
- Chemical etching methods using SO 4 systems, HBr systems, etc. and many other techniques can be applied.
第１図は本発明の原理説明図である。
ａ……上面図、ｂ……側面図、１００……光放
射面、１０１……活性層、１０２……ストライプ
発光領域、１０３……光通過領域、１０４……光
源像、１０５……放出光、第２図は本発明の実施
例説明図である。ａ……上面図、ｂ……側面図、
２００……ｎ形InP基板、２０１……ｎ形InPク
ラツド層、２０２……InGaAsP（波長1.3μｍ）
活性層、２０３……ｐ形InPクラツド層、２０４
……ｐ形InGaAsP（波長1.1μｍ）キヤツプ層、
２０５……SiO2膜、２０６……p+拡散領域、２
０７…ｐ形オーミツク電極金属層、２０８……ｎ
形オーミツク電極金属層、２０９……ダイヤモン
ドヒートシンク、２１０……光放射面、２１１…
…ストライプ発光領域、２１２……発光領域像
（光源像）、２１３……放射光、第３図は本発明の
他の実施例説明図である。ａ……上面図、ｂ……
側面図、３００……ｎ形GaAs基板、３０１……
ｎ形Al0.3Ga0.9Asクラツド層、３０２……
Al0.05Ga0.95As活性層、３０３……ｐ形
Al0.3Ga0.7Asクラツド層、３０４…
Al0.15Ga0.85Asキヤツプ層、３０５……p+拡散領
域、３０６……ｐ形オーミツク電極金属層、３０
７……ｎ形オーミツク電極金属層、３０８……Si
ヒートシンク、３０９……光反射面、３１０……
光放射面、３１１……ストライプ発光領域、３１
２……発光領域像（光源像）、３１３……境界、
３１４……放射光。
FIG. 1 is a diagram explaining the principle of the present invention. a... Top view, b... Side view, 100... Light emitting surface, 101... Active layer, 102... Stripe light emitting region, 103... Light passing region, 104... Light source image, 105... Emitted light , FIG. 2 is an explanatory diagram of an embodiment of the present invention. a...Top view, b...Side view,
200...n-type InP substrate, 201...n-type InP cladding layer, 202...InGaAsP (wavelength 1.3 μm)
Active layer, 203... p-type InP cladding layer, 204
...p-type InGaAsP (wavelength 1.1 μm) cap layer,
205...SiO 2 film, 206...p + diffusion region, 2
07...p-type ohmic electrode metal layer, 208...n
Ohmic electrode metal layer, 209...diamond heat sink, 210...light emitting surface, 211...
. . . Stripe light emitting region, 212 . . . Light emitting region image (light source image), 213 . a...Top view, b...
Side view, 300... n-type GaAs substrate, 301...
N-type Al 0.3 Ga 0.9 As cladding layer , 302 ...
Al 0 . 05 Ga 0 . 95 As active layer, 303...p type
Al 0.3 Ga 0.7 As cladding layer, 304 …
Al 0 . 15 Ga 0 . 85 As cap layer, 305... p + diffusion region, 306... p type ohmic electrode metal layer, 30
7...n-type ohmic electrode metal layer, 308...Si
Heat sink, 309...Light reflecting surface, 310...
Light emitting surface, 311...Striped light emitting area, 31
2... Light emitting area image (light source image), 313... Boundary,
314...Radiant light.
Claims (1)
明層に隣接した活性層に対して傾斜角を有する光
放射面をもち、前記傾斜角θについて前記ストラ
イプ発光領域の長さとsinθ・cosθとの積が前記
透明層の厚さより小さくなる範囲であることを特
徴とする発光ダイオード。1 has a light emitting surface that is perpendicular to the elongated stripe light emitting region and has an inclination angle with respect to the active layer adjacent to the transparent layer, and for the inclination angle θ, the product of the length of the stripe light emitting region and sin θ・cos θ is as described above. A light emitting diode characterized in that the range is smaller than the thickness of a transparent layer.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP15533980A JPS5779682A (en) | 1980-11-05 | 1980-11-05 | Light emitting diode |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP15533980A JPS5779682A (en) | 1980-11-05 | 1980-11-05 | Light emitting diode |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5779682A JPS5779682A (en) | 1982-05-18 |
| JPS6244718B2 true JPS6244718B2 (en) | 1987-09-22 |
Family
ID=15603722
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP15533980A Granted JPS5779682A (en) | 1980-11-05 | 1980-11-05 | Light emitting diode |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5779682A (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2589513B2 (en) * | 1987-10-29 | 1997-03-12 | 三菱電機株式会社 | Edge-emitting LED |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS49111592A (en) * | 1973-02-21 | 1974-10-24 | ||
| JPS5258492A (en) * | 1975-11-10 | 1977-05-13 | Sumitomo Electric Ind Ltd | Semiconductor light emitting device |
-
1980
- 1980-11-05 JP JP15533980A patent/JPS5779682A/en active Granted
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS49111592A (en) * | 1973-02-21 | 1974-10-24 | ||
| JPS5258492A (en) * | 1975-11-10 | 1977-05-13 | Sumitomo Electric Ind Ltd | Semiconductor light emitting device |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5779682A (en) | 1982-05-18 |
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