JPH07193325A - Semiconductor light emitting device - Google Patents
Semiconductor light emitting deviceInfo
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- JPH07193325A JPH07193325A JP33050093A JP33050093A JPH07193325A JP H07193325 A JPH07193325 A JP H07193325A JP 33050093 A JP33050093 A JP 33050093A JP 33050093 A JP33050093 A JP 33050093A JP H07193325 A JPH07193325 A JP H07193325A
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- Prior art keywords
- semiconductor
- light emitting
- emitting device
- region
- refractive index
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Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、光ファイバジャイロあ
るいは光インターコネクトなどの光源に適用される半導
体発光装置に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor light emitting device applied to a light source such as an optical fiber gyro or an optical interconnect.
【０００２】[0002]
【従来の技術】量子井戸層が半導体多層膜（ブラッグ反
射器）で挟まれたマイクロ共振器型光素子は公知である
〔文献：「コヒーレンスと量子光学VI」（ジェー・エッ
チ・エバリーほか編集）プレナムプレス、ニューヨーク
（１９９０）１２４９〜１２５７頁（山本喜久ほか
著）〕。しかし、量子井戸層あるいは量子井戸層に接し
た半導体層には不純物は添加されていない、いわゆるア
ンドープ層になっている。2. Description of the Related Art A microcavity type optical device in which a quantum well layer is sandwiched between semiconductor multilayer films (Bragg reflectors) is known [Reference: "Coherence and Quantum Optics VI" (edited by J. Etch Eberly et al.). Plenum Press, New York (1990) 1249-1257 (Kihisa Yamamoto et al.)]. However, impurities are not added to the quantum well layer or the semiconductor layer in contact with the quantum well layer, which is a so-called undoped layer.
【０００３】[0003]
【発明が解決しようとする課題】マイクロ共振器型光素
子は、低電流動作が期待されているが、高反射率を有す
る多層膜で発光層が挟まれているため、発光層にわずか
な吸収があっても、動作電流が増大してしまうという問
題がある。The microresonator type optical element is expected to operate at a low current, but since the light emitting layer is sandwiched by the multilayer films having a high reflectance, the light emitting layer is slightly absorbed. However, there is a problem that the operating current increases.
【０００４】また、光ファイバジャイロの光源に、半導
体レーザを用いると大きな雑音が発生するという問題が
ある。光ファイバジャイロは、リング状のファイバを右
回りする光と左回りする光の位相差を測定することで、
回転角度を検出するセンサである。このシステムに通常
の半導体レーザを用いると、半導体レーザでは時間的コ
ヒーレンシイが高いため、光学系要素端面からの反射光
や光ファイバ中での後方レイリー散乱光などの戻り光が
信号光と干渉し大きな雑音を発生する。Further, when a semiconductor laser is used as the light source of the optical fiber gyro, there is a problem that a large noise is generated. An optical fiber gyro measures the phase difference between the clockwise and counterclockwise light in a ring-shaped fiber,
It is a sensor that detects a rotation angle. When a normal semiconductor laser is used in this system, the semiconductor laser has high temporal coherency, so that the reflected light from the end face of the optical system element and the return light such as the backward Rayleigh scattered light in the optical fiber interfere with the signal light. Generates a lot of noise.
【０００５】さらに、コンピュータ内の信号接続に光接
続（光インターコネクション）を導入することによっ
て、コンピュータの性能が大幅に向上できる可能性があ
る。しかし、従来の発光素子は動作電流がｍＡ（ミリア
ンペア）のオーダーであるため、光インターコネクト光
源で必要な素子の集積化等が困難であった。Further, by introducing an optical connection (optical interconnection) into a signal connection in the computer, there is a possibility that the performance of the computer can be greatly improved. However, since the operation current of the conventional light emitting element is on the order of mA (milliampere), it is difficult to integrate the elements necessary for the optical interconnect light source.
【０００６】本発明の目的は、上記問題を解決し、戻り
光に対して安定であり、動作電流の極めて低い半導体発
光素子を提供することにある。An object of the present invention is to solve the above problems and to provide a semiconductor light emitting device which is stable against return light and has an extremely low operating current.
【０００７】[0007]
【課題を解決するための手段】上記の目的を達成するた
めに、所定の半導体基板上に、少なくとも第１半導体と
該第１半導体よりも屈折率の大きな第２半導体を周期的
に積層してなる第１半導体領域と、少なくとも第３半導
体と該第３半導体よりも屈折率の大きな第４半導体を周
期的に積層してなる第２半導体領域と、少なくとも電子
と正孔が発光再結合を生じる第５半導体からなる第３半
導体領域が上記第１半導体領域と上記第２半導体領域と
間に挟まれており、上記第２半導体と上記第４半導体が
上記第３半導体領域に接しており、上記第３半導体領域
の実効的な屈折率の大きさが、上記第２半導体と上記第
４半導体の屈折率に比べ小さく、半導体内での発光波長
をλとしたとき第３半導体領域の厚さｄが０．４λ≦ｄ
≦０．６λの関係を満たしている構造において、上記第
５半導体もしくは該第５半導体に接した上記第３半導体
領域内の半導体層の少なくとも一部にｎ型不純物が添加
されていることを特徴とする面発光型の半導体発光装置
を考案した。In order to achieve the above object, at least a first semiconductor and a second semiconductor having a refractive index larger than that of the first semiconductor are periodically laminated on a predetermined semiconductor substrate. And a second semiconductor region formed by periodically stacking at least a third semiconductor and a fourth semiconductor having a refractive index larger than that of the third semiconductor, and at least electrons and holes cause radiative recombination. A third semiconductor region made of a fifth semiconductor is sandwiched between the first semiconductor region and the second semiconductor region, the second semiconductor and the fourth semiconductor are in contact with the third semiconductor region, and The effective refractive index of the third semiconductor region is smaller than the refractive indices of the second semiconductor and the fourth semiconductor, and the thickness d of the third semiconductor region when the emission wavelength in the semiconductor is λ. Is 0.4λ ≦ d
In a structure satisfying a relation of ≦ 0.6λ, an n-type impurity is added to at least a part of the fifth semiconductor or the semiconductor layer in the third semiconductor region in contact with the fifth semiconductor. A surface emitting type semiconductor light emitting device was devised.
【０００８】上記の半導体発光装置において、上記第５
半導体もしくは該第５半導体に接した上記第３半導体領
域内の半導体層の少なくとも一部に添加されているｎ型
不純物の濃度を１×１０18〔／ｃｍ3〕以上にすること
によって、本目的は効果的に達成できる。また、上記の
半導体光装置において、動作電流を発振しきい値以下に
することで大きな効果が得られる。In the above semiconductor light emitting device, the fifth
By adjusting the concentration of the n-type impurity added to at least a part of the semiconductor layer in the third semiconductor region in contact with the semiconductor or the fifth semiconductor to 1 × 10 18 [/ cm 3 ] or more, Can be achieved effectively. Further, in the above semiconductor optical device, a great effect can be obtained by setting the operating current to be equal to or lower than the oscillation threshold.
【０００９】さらに、本目的を達成する他の構造とし
て、所定の半導体基板上に、少なくとも第１半導体と該
第１半導体よりも屈折率の大きな第２半導体を周期的に
積層してなる第１半導体領域と、少なくとも第３半導体
と該第３半導体よりも屈折率の大きな第４半導体を周期
的に積層してなる第２半導体領域と、少なくとも電子と
正孔が発光再結合を生じる第５半導体からなる第３半導
体領域が上記第１半導体領域と上記第２半導体領域と間
に挟まれており、上記第１半導体と上記第３半導体が上
記第３半導体領域に接しており、上記第３半導体領域の
実効的な屈折率の大きさが、上記第１半導体と上記第３
半導体の屈折率に比べ大きく、半導体内での発光波長を
λとしたとき第３半導体領域の厚さｄが０．９λ≦ｄ≦
１．１λの関係を満たしている構造において、上記第５
半導体もしくは該第５半導体に接した上記第３半導体領
域内の半導体層の少なくとも一部にｎ型不純物が添加さ
れていることを特徴とする面発光型の半導体発光装置を
考案した。また、本半導体発光装置において、第５半導
体もしくは該第５半導体に接した上記第３半導体領域内
の半導体層の少なくとも一部に添加されているｎ型不純
物の濃度を１×１０18〔／ｃｍ3〕以上にすることによ
って効果的に目的を達成できる。また、動作電流を発振
しきい値以下にすることで大きな効果が得られる。Further, as another structure for achieving the object, a first semiconductor is formed by periodically stacking at least a first semiconductor and a second semiconductor having a refractive index larger than that of the first semiconductor on a predetermined semiconductor substrate. A semiconductor region, a second semiconductor region formed by periodically stacking at least a third semiconductor and a fourth semiconductor having a refractive index larger than that of the third semiconductor, and a fifth semiconductor in which at least electrons and holes cause radiative recombination. A third semiconductor region consisting of is sandwiched between the first semiconductor region and the second semiconductor region, the first semiconductor and the third semiconductor are in contact with the third semiconductor region, and the third semiconductor region is The effective refractive index magnitudes of the regions are determined by the first semiconductor and the third semiconductor.
It is larger than the refractive index of the semiconductor, and the thickness d of the third semiconductor region is 0.9λ ≦ d ≦, where λ is the emission wavelength in the semiconductor.
In the structure satisfying the relation of 1.1λ,
A surface-emitting type semiconductor light emitting device is devised, wherein an n-type impurity is added to at least a part of the semiconductor layer in the third semiconductor region in contact with the semiconductor or the fifth semiconductor. In the present semiconductor light emitting device, the concentration of the n-type impurity added to at least a part of the fifth semiconductor or the semiconductor layer in the third semiconductor region in contact with the fifth semiconductor may be 1 × 10 18 [/ cm 2]. 3 ] By the above, the purpose can be effectively achieved. Further, a great effect can be obtained by setting the operating current to be equal to or lower than the oscillation threshold.
【００１０】さらに、上記に記載した半導体発光装置を
光源に用いた光ファイバジャイロシステム、および同半
導体発光装置を光インターコネクト用光源に適用したコ
ンピュータシステムを考案した。Further, an optical fiber gyro system using the above-described semiconductor light emitting device as a light source, and a computer system in which the semiconductor light emitting device is applied to a light source for optical interconnection were devised.
【００１１】[0011]
【作用】半導体レーザのしきい電流Ｉthは、一般に、レ
ート方程式（速度方程式）を解くことにより、The threshold current I th of the semiconductor laser is generally obtained by solving the rate equation (velocity equation)
【００１２】[0012]
【数１】 Ｉth＝ｅｎsp／τphβ ……（１） で与えることができる。ここで、ｅは素電荷、ｎspは反
転分布パラメータ、τphは光子寿命、βは自然放出光が
発光モードに結合する割合を表す。通常、屈折率導波型
レーザでは、このβの値は１０-5程度である。しかし、
マイクロ共振器型発光素子の場合、導波路構造が井戸面
内（ｘ−ｙ面とする）において対称ならばβの値は理想
的には０.５にすることができ、しきい電流を通常のレ
ーザに比べ４〜５桁低減できる可能性がある。これは、
例えば図２に示すマイクロ共振器型発光素子の場合、真
空場の定在波２７の腹の位置に量子井戸層２３がくるよ
うに、ブラッグ反射鏡で挟まれた共振器２５の長さｄが
素子内部での発光波長λに等しく（ｄ＝λ）なっている
ことに起因している。しかし、従来のマイクロ共振器構
造では、量子井戸層２３に不純物が添加されていない
（すなわち、アンドープ）ため、量子井戸層自体での光
再吸収が大きい。このことは、反転分布パラメータｎsp
が大きいことに対応しており、（１）式により、しきい
電流が上昇することになる。なお図２において、２はｎ
型低屈折率層、３はｎ型高屈折率層、９はｐ型高屈折率
層、１０はｐ型低屈折率層、２１はｎ型ブラッグ反射
器、２２は高屈折率層、２４は高屈折率層、２６はｐ型
ブラッグ反射器である。## EQU1 ## I th = en sp / τ ph β (1) can be given. Here, e is the elementary charge, n sp is the population inversion parameter, τ ph is the photon lifetime, and β is the ratio of spontaneous emission light coupling to the emission mode. Normally, in a refractive index guided laser, the value of β is about 10 −5 . But,
In the case of a micro-resonator type light emitting device, if the waveguide structure is symmetrical in the well plane (assumed to be the xy plane), the value of β can be ideally set to 0.5, and the threshold current is usually There is a possibility that it can be reduced by 4 to 5 orders of magnitude compared to the laser of. this is,
For example, in the case of the microresonator type light emitting device shown in FIG. 2, the length d of the resonator 25 sandwiched by Bragg reflectors is such that the quantum well layer 23 is located at the antinode of the standing wave 27 of the vacuum field. This is due to the fact that it is equal to the emission wavelength λ inside the element (d = λ). However, in the conventional microresonator structure, since the quantum well layer 23 is not doped with impurities (that is, undoped), light reabsorption in the quantum well layer itself is large. This means that the population inversion parameter n sp
Corresponds to a large value, and the threshold current rises according to equation (1). In FIG. 2, 2 is n
Type low refractive index layer, 3 is an n type high refractive index layer, 9 is a p type high refractive index layer, 10 is a p type low refractive index layer, 21 is an n type Bragg reflector, 22 is a high refractive index layer, and 24 is The high refractive index layer 26 is a p-type Bragg reflector.
【００１３】マイクロ共振器型発光素子は、しきい値以
下の動作電流においても空間的コヒーレンシイが高いの
で、発光ダイオードとしても有望である。よって、次
に、しきい値以下の動作範囲を含めた発光特性について
述べる。図３は、レート方程式を解くことで求めた、放
射レートＳ／τphとポンピングレートＰの関係の計算結
果である。ただし、Ｓは光子数、Ｐは単位時間に活性層
へ注入される電子数であり、動作電流ＩとはＩ＝ｅＰの
関係にある。また、図３の計算では量子井戸層はＧａＡ
ｓ（厚さＬｚ＝１０ｎｍ）、光子寿命τphは１０ｐｓ、
体積Ｖは１０-13ｃｍ3、βは０．５を仮定している。グ
ラフは、それぞれ、点線が従来のアンドープの場合、破
線がｐドープ、実線がｎドープの場合を示している。こ
こで、ドープ量は共に５×１０18ｃｍ-3であり、不純物
から供給された過剰キャリアは１００％量子井戸層に存
在するものと仮定している。図から明らかに、ｎ型不純
物を量子井戸層へ添加することにより、大幅にポンピン
グレートすなわち動作電流を低減できることがわかる。
これは、ｎ型不純物を量子井戸層自体あるいはその近傍
にドーピングすることにより、電子が過剰に量子井戸層
に存在すること起因している。つまり、電子は有効質量
が小さく、伝導帯の広いエネルギー範囲に渡って電子が
存在するため、光吸収によって価電子帯の電子が伝導帯
へ遷移するレートが大幅に低下するからである。実際、
ｎドープ構造では反転分布パラメータｎspは理想値１に
近い値となっている。The micro-resonator type light emitting device has high spatial coherency even at an operating current below a threshold value, and is therefore promising as a light emitting diode. Therefore, next, the light emission characteristics including the operation range below the threshold value will be described. FIG. 3 is a calculation result of the relationship between the radiation rate S / τ ph and the pumping rate P obtained by solving the rate equation. However, S is the number of photons, P is the number of electrons injected into the active layer per unit time, and the operating current I has a relation of I = eP. In the calculation of FIG. 3, the quantum well layer is GaA.
s (thickness Lz = 10 nm), photon lifetime τ ph is 10 ps,
It is assumed that the volume V is 10 -13 cm 3 and β is 0.5. In the graphs, the dotted line shows the case of conventional undoped, the broken line shows the case of p-doped, and the solid line shows the case of n-doped. Here, it is assumed that the doping amounts are both 5 × 10 18 cm −3 , and the excess carriers supplied from the impurities are present in 100% quantum well layers. It is clear from the figure that the pumping rate, that is, the operating current can be significantly reduced by adding the n-type impurity to the quantum well layer.
This is because electrons are excessively present in the quantum well layer by doping the n-type impurity into the quantum well layer itself or in the vicinity thereof. In other words, electrons have a small effective mass, and electrons exist over a wide energy range of the conduction band, so that the rate at which electrons in the valence band transit to the conduction band due to light absorption is significantly reduced. In fact
In the n-doped structure, the population inversion parameter n sp has a value close to the ideal value 1.
【００１４】以上述べたように、ｎ型不純物を量子井戸
層自体、あるいはその近傍にドーピングすることによ
り、低い電流で動作するマイクロ共振器型発光素子が実
現できる。As described above, by doping an n-type impurity into the quantum well layer itself or in the vicinity thereof, a micro-resonator type light emitting device which operates at a low current can be realized.
【００１５】また、図３から明らかなように、発振しき
い値以下の領域において、ｎドープ構造の優位性はより
顕著になる。従って、動作電流がしきい値以下である発
光ダイオードとして本発明の素子を用いると、より大き
な効果がある。特に、次に述べる光ファイバジャイロへ
の応用では、戻り光に対して安定となるように、発光ダ
イオードとして動作させた方が望ましい。Further, as is apparent from FIG. 3, the superiority of the n-doped structure becomes more remarkable in the region below the oscillation threshold. Therefore, when the device of the present invention is used as a light emitting diode whose operating current is less than or equal to the threshold value, there is a greater effect. In particular, in the application to the optical fiber gyro described below, it is desirable to operate as a light emitting diode so as to be stable against return light.
【００１６】光ファイバジャイロの光源として、戻り光
に対して安定に動作する時間的コヒーレンシイの低い発
光素子が要求されている。本発明の発光素子は動作電流
に関わらず指向性が極めて良い。また、動作電流をしき
い値以下に設定すれば、時間的コヒーレンシイを低くで
きる。従って、本発明の発光素子を発光ダイオードとし
て光ファイバジャイロの光源に適用すれば、戻り光に対
して安定であり、かつ高効率なシステムを構成すること
ができる。また、時間的コヒーレンシイが低いことによ
り、外部共振器が形成されないので、出力が安定になる
という利点がある。これは、また同時に波長ゆらぎによ
る出力不安定性を除去できることにもなる。As a light source for an optical fiber gyro, a light emitting element having a low temporal coherency that operates stably with respect to return light is required. The light emitting element of the present invention has extremely good directivity regardless of the operating current. Further, if the operating current is set below the threshold value, temporal coherency can be lowered. Therefore, if the light emitting element of the present invention is applied to a light source of an optical fiber gyro as a light emitting diode, a system that is stable with respect to returning light and highly efficient can be configured. In addition, since the temporal coherency is low, an external resonator is not formed, so that there is an advantage that the output becomes stable. This also makes it possible to eliminate output instability due to wavelength fluctuations.
【００１７】[0017]
（実施例１）本発明の第１の実施例を図１を用いて説明
する。まず、本発明の半導体発光装置の作製方法につい
て述べる。(Embodiment 1) A first embodiment of the present invention will be described with reference to FIG. First, a method for manufacturing the semiconductor light emitting device of the present invention will be described.
【００１８】ｎ−ＧａＡｓ（１００）面の基板１上に、
分子線エピタキシ（ＭＢＥ）法により、ｎ−ＡｌＡｓの
低屈折率層２とｎ−Ｇａ0.8Ａｌ0.2Ａｓの高屈折率層３
を２５周期積層し、ｎ型ブラッグ反射器４を形成する。
ただし、各層の厚さは素子内部での波長λの１／４とす
る。また、ドーパントはＳｉであり、ドナー濃度ＮDは
３×１０18〔／ｃｍ3〕とする。次に、アンドープＡｌ
Ａｓ層５、ｎドープＧａＡｓ量子井戸層（厚さ１０ｎ
ｍ、ドナー濃度５×１０18〔／ｃｍ3〕）６、アンドー
プＡｌＡｓ層７から成る共振器８を設ける。ただし、共
振器８の厚さはλ／２とする。続けて、Ｐ−Ｇａ0.8Ａ
ｌ0.2Ａｓの高屈折率層９（厚さλ／４、アクセプタ濃
度ＮA＝４×１０18〔／ｃｍ3〕）とｐ−ＡｌＡｓの低屈
折率層１０（厚さλ／４、ＮA＝４×１０18〔／ｃ
ｍ3〕）を２０周期積層し、ｐ型ブラッグ反射器１１を
形成する。また、電極との接触抵抗を下げるため、ｐ−
ＧａＡｓキャップ層１２を設ける。最後に、ＡｕＧｅＮ
ｉ−Ｃｒ−Ａｕを蒸着してｎ型電極１３を、また、Ｔｉ
−Ｍｏ−Ａｕを蒸着してｐ型電極１４を形成し、通常の
エッチング法によりｐ型電極の一部を除去することによ
り３μｍφの円形の出射窓１５を設け、図１に示す実施
例の半導体発光装置を作製する。On the substrate 1 of n-GaAs (100) surface,
By the molecular beam epitaxy (MBE) method, a low refractive index layer 2 of n-AlAs and a high refractive index layer 3 of n-Ga 0.8 Al 0.2 As
Are laminated for 25 cycles to form the n-type Bragg reflector 4.
However, the thickness of each layer is 1/4 of the wavelength λ inside the element. The dopant is Si and the donor concentration N D is 3 × 10 18 [/ cm 3 ]. Next, undoped Al
As layer 5, n-doped GaAs quantum well layer (thickness: 10 n
m, donor concentration 5 × 10 18 [/ cm 3 ]) 6, and a resonator 8 composed of an undoped AlAs layer 7. However, the thickness of the resonator 8 is λ / 2. Continuously, P-Ga 0.8 A
l 0.2 As high-refractive index layer 9 (thickness λ / 4, acceptor concentration N A = 4 × 10 18 [/ cm 3 ]) and p-AlAs low-refractive index layer 10 (thickness λ / 4, N A = 4 × 10 18 [/ c
m 3 ]) are laminated for 20 cycles to form the p-type Bragg reflector 11. In addition, in order to reduce the contact resistance with the electrode, p-
A GaAs cap layer 12 is provided. Finally, AuGeN
i-Cr-Au is deposited to form the n-type electrode 13 and Ti.
-Mo-Au is vapor-deposited to form the p-type electrode 14, and a part of the p-type electrode is removed by an ordinary etching method to provide a circular emission window 15 of 3 [mu] m [phi], and the semiconductor of the embodiment shown in FIG. A light emitting device is manufactured.
【００１９】上記実施例の装置において、１０μＡ以下
の低電流動作が可能である。また、光ファイバージャイ
ロの光源として本実施例の半導体発光装置を用いること
により、戻り光に対して安定なシステムを構成できる。
また上記実施例では共振器８の厚さをλ／２としたが、
この厚さは０．４λ〜０．６λの範囲であれば同様の効
果を得ることができる。The device of the above embodiment can operate at a low current of 10 μA or less. Further, by using the semiconductor light emitting device of the present embodiment as the light source of the optical fiber gyro, it is possible to construct a stable system against return light.
In the above embodiment, the thickness of the resonator 8 is λ / 2,
The same effect can be obtained if the thickness is in the range of 0.4λ to 0.6λ.
【００２０】（実施例２）本発明の第２の実施例を図４
と図５を用いて説明する。図５は図４の多層領域の断面
図である。まず、本発明の半導体発光装置の作製方法に
ついて述べる。(Embodiment 2) A second embodiment of the present invention is shown in FIG.
Will be described with reference to FIG. FIG. 5 is a cross-sectional view of the multi-layer region of FIG. First, a method for manufacturing the semiconductor light emitting device of the present invention will be described.
【００２１】図４に示すｎ−ＧａＡｓ（１００）面の基
板１上に、ＭＢＥ法により、図５に示すｎ−ＡｌＡｓの
低屈折率層３１（厚さλ／４、ドナー濃度ＮD＝３×１
０18〔／ｃｍ3〕）とｎ−ＧａＡｓの高屈折率層（厚さ
λ／４、ＮD＝３×１０18〔／ｃｍ3〕）を２５．５周期
積層し、ｎ型ブラッグ反射器３３を形成する。次に、ア
ンドープＧａ0.8Ａｌ0.2Ａｓ層３４、ｎドープＩｎ0.2
Ｇａ0.8Ａｓ歪み量子井戸層（厚さ７ｎｍ、ドナー濃度
５×１０18〔／ｃｍ3〕）３５、アンドープ層Ｇａ0.8Ａ
ｌ0.2Ａｓ層３６から成る共振器３７を設ける。ただ
し、共振器３７の厚さはλとする。続けて、ｐ−ＡｌＡ
ｓの低屈折率層３８（厚さλ／４、ＮA＝４×１０
18〔／ｃｍ3〕）とｐ−ＧａＡｓの高屈折率層３９（厚
さλ／４、ＮA＝４×１０18〔／ｃｍ3〕）を２０．５周
期積層し、ｐ型ブラック反射器４０を形成する。また、
電極との接触抵抗を下げるため、ｐ−ＧａＡｓキャップ
層１２を設ける。On the n-GaAs (100) plane substrate 1 shown in FIG. 4, a low refractive index layer 31 (thickness λ / 4, donor concentration N D = 3 of n-AlAs shown in FIG. 5 is formed by the MBE method. × 1
0 18 [/ cm 3 ]) and a high refractive index layer of n-GaAs (thickness λ / 4, N D = 3 × 10 18 [/ cm 3 ]) are laminated for 25.5 periods to form an n-type Bragg reflector. 33 is formed. Next, the undoped Ga 0.8 Al 0.2 As layer 34 and the n-doped In 0.2
Ga 0.8 As strained quantum well layer (thickness 7 nm, donor concentration 5 × 10 18 [/ cm 3 ]) 35, undoped layer Ga 0.8 A
A resonator 37 composed of a 0.2 As layer 36 is provided. However, the thickness of the resonator 37 is λ. Continuously, p-AlA
s low refractive index layer 38 (thickness λ / 4, N A = 4 × 10
18 [/ cm 3 ]) and a high refractive index layer 39 of p-GaAs (thickness λ / 4, N A = 4 × 10 18 [/ cm 3 ]) are laminated for 20.5 periods to form a p-type black reflector. 40 is formed. Also,
The p-GaAs cap layer 12 is provided to reduce the contact resistance with the electrodes.
【００２２】実施例１の場合、導波路構造が量子井戸面
内（ｘ−ｙ面内）で対称であるため、光偏向方向がｘ−
ｙ面内で自由であり、自然放出光が発光モードに結合す
る割合βの最大値は０．５になる。一方、図４の構造
は、さらに、βの値を向上させるために、エッチングに
よりメサ形状を楕円形（長軸の長さ４μｍ、短軸の長さ
２μｍ）にする。ここで、エッチングはｎ型ブラッグ反
射器３３に到達するように行う。最後に、ＡｕＧｅＮｉ
−Ｃｒ−Ａｕを蒸着してｎ型電極１３を設け、さらに、
メサの側部をポリイミド４１で埋め込んだ後、Ｔｉ−Ｍ
ｏ−Ａｕを蒸着してｐ型電極１４を形成する。In the case of Example 1, since the waveguide structure is symmetrical in the quantum well plane (in the xy plane), the light deflection direction is x-.
It is free in the y-plane, and the maximum value of the ratio β at which spontaneous emission light is coupled to the emission mode is 0.5. On the other hand, in the structure of FIG. 4, in order to further improve the value of β, the mesa shape is made into an ellipse (long axis length 4 μm, short axis length 2 μm) by etching. Here, the etching is performed so as to reach the n-type Bragg reflector 33. Finally, AuGeNi
-Cr-Au is vapor-deposited to provide the n-type electrode 13, and
After embedding the side of the mesa with polyimide 41, Ti-M
The p-type electrode 14 is formed by evaporating o-Au.
【００２３】上記実施例の装置ではメサ構造になってい
るため、発光領域の体積が実施例１よりも実効的に小さ
い。よって、１μＡ以下の低電流動作が可能である。ま
た、光ファイバージャイロの光源として本実施例の半導
体発光装置を用いることにより、戻り光に対して安定な
システムを構成できる。また上記実施例では共振器３７
の厚さをλとしたが、この厚さは０．９λ〜１．１λの
範囲であれば同様の効果を得ることができる。Since the device of the above embodiment has the mesa structure, the volume of the light emitting region is effectively smaller than that of the first embodiment. Therefore, low current operation of 1 μA or less is possible. Further, by using the semiconductor light emitting device of the present embodiment as the light source of the optical fiber gyro, it is possible to construct a stable system against return light. Further, in the above embodiment, the resonator 37
Although the thickness is set to λ, the same effect can be obtained if the thickness is in the range of 0.9λ to 1.1λ.
【００２４】なお本発明は、実施例に示した以外の構造
にも有効である。例えば、素子の直列抵抗を低減するた
めに、ブラッグ反射器を形成している高屈折率層と低屈
折率層の間にグレーデッド層（組成が徐々に変化した
層）を設けた構造にも適用できる。また、本実施例で示
した以外の材料、例えば波長１．２〜１．６μｍが得ら
れるＩｎＧａＡｓＰ／ＩｎＰ系や０．３〜０．６μｍの
波長が実現できるII−VI族の材料でも有効である。The present invention is also effective for structures other than those shown in the embodiments. For example, in order to reduce the series resistance of the device, a structure in which a graded layer (layer whose composition is gradually changed) is provided between the high refractive index layer and the low refractive index layer forming the Bragg reflector is also available. Applicable. Further, materials other than those shown in the present embodiment, for example, InGaAsP / InP system which can obtain a wavelength of 1.2 to 1.6 μm and II-VI group materials which can realize a wavelength of 0.3 to 0.6 μm are also effective. is there.
【００２５】[0025]
【発明の効果】本発明によれば、量子井戸型発光層にｎ
型不純物が高ドープされているので、発光層自体での光
吸収量を低減できる。従って、マイクロ共振器型発光素
子の動作電流を大幅に低減できる。さらに、本発明の発
光素子は戻り光に対して安定であり、光出力の変動も少
ないため、本発光素子を光ファイバージャイロや光イン
ターコネクトが導入されているコンピュータシステムに
適用することで、システムの高性能化が図れる。According to the present invention, the quantum well type light emitting layer has an n-type structure.
Since the type impurities are highly doped, the amount of light absorption in the light emitting layer itself can be reduced. Therefore, the operating current of the micro-resonator type light emitting device can be significantly reduced. Further, since the light emitting element of the present invention is stable with respect to return light and has little fluctuation in optical output, application of the light emitting element to a computer system in which an optical fiber gyro or an optical interconnect is introduced makes it possible to improve system performance. Performance can be improved.
【図１】本発明の実施例の半導体発光装置の断面図。FIG. 1 is a sectional view of a semiconductor light emitting device according to an embodiment of the present invention.
【図２】従来型半導体発光装置の多層領域の断面図。FIG. 2 is a cross-sectional view of a multi-layer region of a conventional semiconductor light emitting device.
【図３】発光レートとポンピングレートの関係を示す計
算図。FIG. 3 is a calculation diagram showing a relationship between a light emission rate and a pumping rate.
【図４】本発明の実施例の半導体発光装置の断面図。FIG. 4 is a sectional view of a semiconductor light emitting device according to an embodiment of the present invention.
【図５】図４の多層領域の断面図。5 is a cross-sectional view of the multi-layer region of FIG.
１…ｎ型基板、２，３１…ｎ型低屈折率層、３，３２…
ｎ型高屈折率層、４，２１，３３…ｎ型ブラッグ反射
器、５，７…低屈折率層、６，３５…ｎドープ量子井戸
層、８，２５，３７…共振器、９，３９…ｐ型高屈折率
層、１０，３８…ｐ型低屈折率層、１１，２６，４０…
ｐ型ブラッグ反射器、１２…ｐ型キャップ層、１３…ｎ
型電極、１４…ｐ型電極、１５…出射窓、２２，２４，
３４，３６…高屈折率層、２３…アンドープ量子井戸
層、２７…真空場の定在波、４１…ポリイミド。1 ... n type substrate, 2,31 ... n type low refractive index layer, 3,32 ...
n-type high refractive index layer, 4, 21, 33 ... n-type Bragg reflector, 5, 7 ... low refractive index layer, 6, 35 ... n-doped quantum well layer, 8, 25, 37 ... resonator, 9, 39 ... p-type high refractive index layer, 10, 38 ... p-type low refractive index layer 11, 26, 40 ...
p-type Bragg reflector, 12 ... p-type cap layer, 13 ... n
Mold electrode, 14 ... P-type electrode, 15 ... Exit window, 22, 24,
34, 36 ... High refractive index layer, 23 ... Undoped quantum well layer, 27 ... Standing wave in vacuum field, 41 ... Polyimide.
フロントページの続き (72)発明者 山西 正道 広島県東広島市鏡山一丁目４番１号Continued Front Page (72) Masamichi Yamanishi 1-4-1, Kagamiyama, Higashihiroshima City, Hiroshima Prefecture
Claims (8)
導体と該第１半導体よりも屈折率の大きな第２半導体を
周期的に積層してなる第１半導体領域と、少なくとも第
３半導体と該第３半導体よりも屈折率の大きな第４半導
体を周期的に積層してなる第２半導体領域と、上記第１
半導体領域と上記第２半導体領域との間に挟まれた少な
くとも電子と正孔が発光再結合を生じる第５半導体から
なる第３半導体領域とを有し、上記第２半導体と上記第
４半導体は上記第３半導体領域に接しており、上記第３
半導体領域の実効的な屈折率の大きさは上記第２半導体
と上記第４半導体の屈折率に比べ小さく、半導体内での
発光波長をλとしたとき上記第３半導体領域の厚さｄが
０．４λ≦ｄ≦０．６λの関係を満たしており、上記第
５半導体もしくは該第５半導体に接した上記第３半導体
領域内の半導体層の少なくとも一部にｎ型不純物が添加
されていることを特徴とする半導体発光装置。1. A first semiconductor region formed by periodically stacking at least a first semiconductor and a second semiconductor having a refractive index larger than that of the first semiconductor on a predetermined semiconductor substrate, at least a third semiconductor, and A second semiconductor region formed by periodically stacking a fourth semiconductor having a refractive index larger than that of the third semiconductor;
At least an electron and a hole sandwiched between the semiconductor region and the second semiconductor region include a third semiconductor region made of a fifth semiconductor that causes radiative recombination, and the second semiconductor and the fourth semiconductor are Is in contact with the third semiconductor region,
The effective refractive index of the semiconductor region is smaller than the refractive indices of the second semiconductor and the fourth semiconductor, and the thickness d of the third semiconductor region is 0 when the emission wavelength in the semiconductor is λ. .4λ ≦ d ≦ 0.6λ, and n-type impurities are added to at least a part of the fifth semiconductor or the semiconductor layer in the third semiconductor region in contact with the fifth semiconductor. And a semiconductor light emitting device.
した上記第３半導体領域内の半導体層の少なくとも一部
に添加されているｎ型不純物の濃度が１×１０18〔／ｃ
ｍ3〕以上であることを特徴とする請求項１記載の半導
体発光装置。2. The concentration of the n-type impurity added to at least a part of the semiconductor layer in the third semiconductor region in contact with the fifth semiconductor or the fifth semiconductor is 1 × 10 18 [/ c
m 3 ] or more, The semiconductor light emitting device according to claim 1, wherein
特徴とする請求項１又は２記載の半導体発光装置。3. The semiconductor light emitting device according to claim 1, wherein the operating current is equal to or lower than the oscillation threshold value.
導体と該第１半導体よりも屈折率の大きな第２半導体を
周期的に積層してなる第１半導体領域と、少なくとも第
３半導体と該第３半導体よりも屈折率の大きな第４半導
体を周期的に積層してなる第２半導体領域と、上記第１
半導体領域と上記第２半導体領域との間に挟まれた少な
くとも電子と正孔が発光再結合を生じる第５半導体から
なる第３半導体領域とを有し、上記第１半導体と上記第
３半導体は上記第３半導体領域に接しており、上記第３
半導体領域の実効的な屈折率の大きさは、上記第１半導
体と上記第３半導体の屈折率に比べ大きく、半導体内で
の発光波長をλとしたとき第３半導体領域の厚さｄが
０．９λ≦ｄ≦１．１λの関係を満たしており、上記第
５半導体もしくは該第５半導体に接した上記第３半導体
領域内の半導体層の少なくとも一部にｎ型不純物が添加
されていることを特徴とする半導体発光装置。4. A first semiconductor region formed by periodically stacking at least a first semiconductor and a second semiconductor having a refractive index larger than that of the first semiconductor on a predetermined semiconductor substrate, at least a third semiconductor and the third semiconductor region. A second semiconductor region formed by periodically stacking a fourth semiconductor having a refractive index larger than that of the third semiconductor;
At least an electron and a hole sandwiched between the semiconductor region and the second semiconductor region include a third semiconductor region made of a fifth semiconductor that causes radiative recombination, and the first semiconductor and the third semiconductor are Is in contact with the third semiconductor region,
The effective refractive index of the semiconductor region is larger than the refractive indices of the first semiconductor and the third semiconductor, and the thickness d of the third semiconductor region is 0 when the emission wavelength in the semiconductor is λ. .9λ ≦ d ≦ 1.1λ, and n-type impurities are added to at least a part of the fifth semiconductor or the semiconductor layer in the third semiconductor region in contact with the fifth semiconductor. And a semiconductor light emitting device.
した上記第３半導体領域内の半導体層の少なくとも一部
に添加されているｎ型不純物の濃度が１×１０18〔／ｃ
ｍ3〕以上であることを特徴とする請求項４記載の半導
体発光装置。5. The concentration of the n-type impurity added to at least a part of the semiconductor layer in the third semiconductor region in contact with the fifth semiconductor or the fifth semiconductor has a concentration of 1 × 10 18 [/ c].
m 3 ] or more, the semiconductor light emitting device according to claim 4.
特徴とする請求項４又は５記載の半導体発光装置。6. The semiconductor light emitting device according to claim 4, wherein the operating current is equal to or lower than an oscillation threshold value.
発光装置を光源に用いた光ファイバジャイロシステム。7. An optical fiber gyro system using the semiconductor light emitting device according to claim 1 as a light source.
発光装置を光インターコネクト用光源に用いたコンピュ
ータシステム。8. A computer system using the semiconductor light emitting device according to claim 1 as a light source for an optical interconnect.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP33050093A JPH07193325A (en) | 1993-12-27 | 1993-12-27 | Semiconductor light emitting device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP33050093A JPH07193325A (en) | 1993-12-27 | 1993-12-27 | Semiconductor light emitting device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH07193325A true JPH07193325A (en) | 1995-07-28 |
Family
ID=18233323
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP33050093A Pending JPH07193325A (en) | 1993-12-27 | 1993-12-27 | Semiconductor light emitting device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH07193325A (en) |
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH09232631A (en) * | 1996-02-27 | 1997-09-05 | Sumitomo Chem Co Ltd | 3-5 compound semiconductor light emitting device |
| EP1035621A1 (en) * | 1999-02-11 | 2000-09-13 | CSEM Centre Suisse d'Electronique et de Microtechnique S.A. - Recherche et Développement | A semiconductor laser device and method for fabrication thereof |
| JP2002185043A (en) * | 2001-10-19 | 2002-06-28 | Sumitomo Chem Co Ltd | Method of manufacturing class iii-v compound semiconductor light-emitting element |
| JP2006041013A (en) * | 2004-07-23 | 2006-02-09 | Yokohama National Univ | Light control element, light emitting element, and optical circuit device |
| JP2009239176A (en) * | 2008-03-28 | 2009-10-15 | Dowa Electronics Materials Co Ltd | Light emitting element |
| US7881358B2 (en) | 2006-12-27 | 2011-02-01 | Nec Corporation | Surface emitting laser |
| US7974328B2 (en) | 2007-03-22 | 2011-07-05 | Nec Corporation | Surface-emission type semiconductor laser |
| JP2011166108A (en) * | 2010-01-15 | 2011-08-25 | Ricoh Co Ltd | Surface emitting laser element, surface emitting laser array, optical scanner, and image forming apparatus |
-
1993
- 1993-12-27 JP JP33050093A patent/JPH07193325A/en active Pending
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH09232631A (en) * | 1996-02-27 | 1997-09-05 | Sumitomo Chem Co Ltd | 3-5 compound semiconductor light emitting device |
| EP1035621A1 (en) * | 1999-02-11 | 2000-09-13 | CSEM Centre Suisse d'Electronique et de Microtechnique S.A. - Recherche et Développement | A semiconductor laser device and method for fabrication thereof |
| JP2002185043A (en) * | 2001-10-19 | 2002-06-28 | Sumitomo Chem Co Ltd | Method of manufacturing class iii-v compound semiconductor light-emitting element |
| JP2006041013A (en) * | 2004-07-23 | 2006-02-09 | Yokohama National Univ | Light control element, light emitting element, and optical circuit device |
| US7881358B2 (en) | 2006-12-27 | 2011-02-01 | Nec Corporation | Surface emitting laser |
| US7974328B2 (en) | 2007-03-22 | 2011-07-05 | Nec Corporation | Surface-emission type semiconductor laser |
| JP2009239176A (en) * | 2008-03-28 | 2009-10-15 | Dowa Electronics Materials Co Ltd | Light emitting element |
| JP2011166108A (en) * | 2010-01-15 | 2011-08-25 | Ricoh Co Ltd | Surface emitting laser element, surface emitting laser array, optical scanner, and image forming apparatus |
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