JP2008209863A - Semiconductor modulator and optical semiconductor device - Google Patents

Semiconductor modulator and optical semiconductor device Download PDF

Info

Publication number
JP2008209863A
JP2008209863A JP2007048977A JP2007048977A JP2008209863A JP 2008209863 A JP2008209863 A JP 2008209863A JP 2007048977 A JP2007048977 A JP 2007048977A JP 2007048977 A JP2007048977 A JP 2007048977A JP 2008209863 A JP2008209863 A JP 2008209863A
Authority
JP
Japan
Prior art keywords
quantum well
layer
semiconductor
strain
well structure
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.)
Granted
Application number
JP2007048977A
Other languages
Japanese (ja)
Other versions
JP5062732B2 (en
Inventor
Masakazu Arai
昌和 荒井
Yasuhiro Kondo
康洋 近藤
Wataru Kobayashi
亘 小林
Kyoichi Kinoshita
恭一 木下
Shinichi Yoda
眞一 依田
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Nippon Telegraph and Telephone Corp
Japan Aerospace Exploration Agency JAXA
Original Assignee
Nippon Telegraph and Telephone Corp
Japan Aerospace Exploration Agency JAXA
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Nippon Telegraph and Telephone Corp, Japan Aerospace Exploration Agency JAXA filed Critical Nippon Telegraph and Telephone Corp
Priority to JP2007048977A priority Critical patent/JP5062732B2/en
Publication of JP2008209863A publication Critical patent/JP2008209863A/en
Application granted granted Critical
Publication of JP5062732B2 publication Critical patent/JP5062732B2/en
Expired - Fee Related legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Abstract

<P>PROBLEM TO BE SOLVED: To provide a semiconductor modulator improving a high-temperature operation characteristic. <P>SOLUTION: The semiconductor modulator has such a configuration that an InGaAs/InAlAs quantum well layer 3 is formed by arranging an InAlAs barrier layer which is lattice-matched with a substrate on both sides of an InGaAs compressively-strained quantum well layer which is formed as light absorption layer, on a semiconductor crystal InGaAs substrate 1 of ternary mixed crystal. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

本発明は、半導体変調器における光吸収特性を向上するため、歪量子井戸構造の高品質化を実現する技術であって、広い環境温度範囲で安定して動作する光半導体装置に関するものである。   The present invention relates to a technique for realizing a high quality strained quantum well structure in order to improve light absorption characteristics in a semiconductor modulator, and relates to an optical semiconductor device that operates stably in a wide environmental temperature range.

従来、通信波長帯である波長１．３μｍと１．５５μｍで用いることができる電界吸収型変調器は、バンドギャップ、格子定数の関係上作製しやすいＩｎＰ基板上にＩｎＧａＡｓＰ／ＩｎＧａＡｓＰ量子井戸を用いて作製されてきた。
電界吸収変調器に量子井戸構造を用いると量子閉じ込めシュタルク効果が利用できる。この効果は量子井戸に垂直に電界を印加することにより、電子と正孔が対になった励起子による光吸収ピークが変化し、小さい印加電圧においても大きな吸収係数変化をもたらすものである。
このような従来の半導体変調器においては、通常、光吸収特性の改善のために、量子井戸中へのキャリアの閉じ込めを十分確保することが重要になる。 Conventionally, electroabsorption modulators that can be used at wavelengths of 1.3 μm and 1.55 μm, which are communication wavelength bands, use InGaAsP / InGaAsP quantum wells on InP substrates that are easy to fabricate due to the band gap and lattice constant. Have been made.
If a quantum well structure is used for the electroabsorption modulator, the quantum confined Stark effect can be used. This effect is that when an electric field is applied perpendicularly to the quantum well, the light absorption peak due to excitons in which electrons and holes are paired changes, and a large change in absorption coefficient occurs even at a small applied voltage.
In such a conventional semiconductor modulator, it is usually important to ensure sufficient confinement of carriers in the quantum well in order to improve light absorption characteristics.

しかし、従来のＩｎＰ基板上光半導体変調器では、伝導帯側の量子井戸層と障壁層間のバンドオフセットが小さいために、高温条件下にすると電子のオーバーフローによる光吸収の低下が生じ、消光比の低下が引き起こされる。このため、ペルチェクーラー等の温度調整器の使用が不可欠であった。   However, in a conventional optical semiconductor modulator on an InP substrate, since the band offset between the quantum well layer and the barrier layer on the conduction band side is small, light absorption is reduced due to an overflow of electrons under high temperature conditions, and the extinction ratio is reduced. A decline is caused. For this reason, it was indispensable to use a temperature regulator such as a Peltier cooler.

また同じＩｎＰ基板上において、ＩｎＧａＡｓＰ系より大きなバンドオフセットを持つといわれるＡｌＧａＩｎＡｓ系の光半導体変調器も開発されているが、高温環境でのペルチェフリー使用を考慮した場合、消光比の低下を抑制するにはまだ不十分であった。   An AlGaInAs optical semiconductor modulator, which is said to have a larger band offset than the InGaAsP system on the same InP substrate, has also been developed. It was still not enough.

一方、ＧａＡｓ基板上のＩｎＧａＡｓ歪量子井戸構造は前述のＩｎＰ基板に比べ、大きな伝導帯バンドオフセットをもつ。しかしながら、１．３μｍ帯の光の吸収係数を制御するためには、Ｉｎ組成を４０％から５０％程度に高める必要がある。Ｉｎ組成の増加とともに、ＧａＡｓ基板との格子不整合が大きくなり、３次元成長やミスフィット転位が生じる。そのため、１．３μｍ以上の波長帯での高品質な量子井戸層の形成は困難である。   On the other hand, the InGaAs strained quantum well structure on the GaAs substrate has a larger conduction band offset than the above-described InP substrate. However, in order to control the light absorption coefficient in the 1.3 μm band, it is necessary to increase the In composition from about 40% to about 50%. As the In composition increases, the lattice mismatch with the GaAs substrate increases, resulting in three-dimensional growth and misfit dislocations. For this reason, it is difficult to form a high-quality quantum well layer in a wavelength band of 1.3 μm or more.

この格子不整合とバンドオフセットの問題を改善する手段として、ＧａＡｓより格子定数が大きいＩｎＧａＡｓ３元基板上の歪量子井戸構造が提案された（例えば、非特許文献１参照）。   As means for improving the problem of lattice mismatch and band offset, a strained quantum well structure on an InGaAs ternary substrate having a lattice constant larger than that of GaAs has been proposed (for example, see Non-Patent Document 1).

図２は、ＩｎＧａＡｓ歪量子井戸層の歪とバンドギャップ波長との関係である。量子井戸層の厚さは１０ｎｍとしている。ここで、ＩｎＧａＡｓ障壁層は基板に格子整合する組成を用いた。
１．３μｍの光の吸収波長を実現するための量子井戸層の歪量は、ＧａＡｓ基板上では３．２％、Ｉｎ組成０．１のＩｎＧａＡｓ基板では２．３％、Ｉｎ組成０．２のＩｎＧａＡｓ基板では１．８％となる。
この構造では、量子井戸層と障壁層のＩｎ組成の差を大きくするほどバンド不連続も大きくなるためキャリアオーバーフローの抑制が可能となり、温度特性が向上する。しかしながら、量子井戸層の歪量が大きくなるため、結晶性の劣化が起こる。そのため３元基板上高歪量子井戸の結晶性向上技術が必要となる。 FIG. 2 shows the relationship between the strain of the InGaAs strained quantum well layer and the band gap wavelength. The thickness of the quantum well layer is 10 nm. Here, the InGaAs barrier layer has a composition lattice-matched to the substrate.
The strain amount of the quantum well layer for realizing the light absorption wavelength of 1.3 μm is 3.2% on the GaAs substrate, 2.3% on the InGaAs substrate having the In composition 0.1, and 0.2% on the In composition 0.2. For an InGaAs substrate, it is 1.8%.
In this structure, as the difference in In composition between the quantum well layer and the barrier layer increases, the band discontinuity increases, so that carrier overflow can be suppressed and temperature characteristics are improved. However, since the amount of strain in the quantum well layer increases, the crystallinity deteriorates. Therefore, a technique for improving the crystallinity of a high strain quantum well on a ternary substrate is required.

また、半導体変調器の高温動作特性に影響が大きいものとして、素子の熱抵抗の問題がある。ＩｎＧａＡｓ３元基板を半導体変調器構造へ用いた場合、結晶の混晶化により、組成に対して物性値が比例せず、非線形因子が存在する。そのため、２元に比べ３元や４元混晶の物性値は２次関数的な振る舞いを示す。例えばＩｎＧａＡｓは、そのもとになるＩｎＡｓやＧａＡｓに比べ、材料の熱抵抗が上昇する問題がある。図８は、ＩｎＧａＡｓの熱抵抗率のＩｎ組成依存性である。これによるとＩｎ0.3Ｇａ0.7ＡｓではＧａＡｓの熱抵抗率２．３に比べ８倍程度高いことがわかる。クラッド層や光吸収層の熱抵抗が上昇することにより、光吸収層で発生した熱がヒートシンクへ逃げる効率が低下し、光吸収層の温度上昇につながる。 Moreover, there is a problem of the thermal resistance of the element as having a large influence on the high-temperature operating characteristics of the semiconductor modulator. When an InGaAs ternary substrate is used in a semiconductor modulator structure, the physical property value is not proportional to the composition due to crystal mixing, and there is a nonlinear factor. Therefore, the physical property values of ternary and quaternary mixed crystals show a quadratic function behavior compared to binary. For example, InGaAs has a problem that the thermal resistance of the material is increased as compared with InAs and GaAs as a base material. FIG. 8 shows the In composition dependence of the thermal resistivity of InGaAs. According to this, it can be seen that In 0.3 Ga 0.7 As is about eight times higher than the thermal resistivity 2.3 of GaAs. As the thermal resistance of the cladding layer and the light absorption layer increases, the efficiency with which the heat generated in the light absorption layer escapes to the heat sink decreases, leading to an increase in the temperature of the light absorption layer.

さらに、同一基板上に半導体レーザを作製し、集積化した場合には、隣接するレーザからの発熱も加わるため、素子の熱抵抗の影響は大きくなる。   Further, when a semiconductor laser is fabricated and integrated on the same substrate, heat from the adjacent laser is also added, so that the influence of the thermal resistance of the element is increased.

K.Otsubo, et Al.,IEEE Photonics Technology Letter, Vol.10, No.8, pp.1073−1075, 1998.K. Otsubo, et Al., IEEE Photonics Technology Letter, Vol. 10, No. 8, pp.1073-1075, 1998.

以上のように、通信用半導体変調器の温度特性向上のためには３元基板上歪量子井戸変調器が有効であるが、吸収波長を通信波長帯である１．３μｍ以上にするためには量子井戸層の高歪化が必要であり、そのためミスフィット転位の発生等による結晶性の劣化が問題であった。また、高温動作特性の向上のためには、３元結晶を用いた場合の熱抵抗上昇も問題であった。本発明は以上のような点に鑑みてなされたもので、その目的とするところは優れた温度特性が期待されるＩｎＧａＡｓ３元基板上の高歪量子井戸構造の結晶性の向上と熱抵抗の低減にある。   As described above, a ternary substrate strain quantum well modulator is effective for improving the temperature characteristics of a communication semiconductor modulator, but in order to increase the absorption wavelength to 1.3 μm or more, which is the communication wavelength band. It is necessary to increase the strain of the quantum well layer, and therefore crystallinity deterioration due to the occurrence of misfit dislocations has been a problem. In addition, an increase in thermal resistance when using a ternary crystal has also been a problem for improving high-temperature operating characteristics. The present invention has been made in view of the above points, and its object is to improve the crystallinity and reduce the thermal resistance of a high strain quantum well structure on an InGaAs ternary substrate where excellent temperature characteristics are expected. It is in.

上記の課題を解決するための第１の発明に係る半導体変調器は、３元混晶の半導体結晶Ｉｎ(ｘ)Ｇａ(１−ｘ)Ａｓからなる基板の上に、光吸収層として形成される歪量子井戸構造において、前記歪量子井戸構造は、圧縮歪量子井戸層と、歪量が０より大きく１．５％以下である引っ張り歪障壁層とからなることを特徴とする。   A semiconductor modulator according to a first invention for solving the above problems is formed as a light absorption layer on a substrate made of a ternary mixed crystal semiconductor crystal In (x) Ga (1-x) As. In the strained quantum well structure, the strained quantum well structure is characterized by comprising a compressive strained quantum well layer and a tensile strained barrier layer having a strain amount greater than 0 and not more than 1.5%.

上記の課題を解決するための第２の発明に係る半導体変調器は、３元混晶の半導体結晶Ｉｎ(ｘ)Ｇａ(１−ｘ)Ａｓからなる基板の上に、光吸収層として形成される歪量子井戸構造において、前記歪量子井戸構造は、圧縮歪量子井戸層と、ＩｎまたはＡｌまたはＧａとＡｓを含む障壁層とからなることを特徴とする。   A semiconductor modulator according to a second invention for solving the above problems is formed as a light absorption layer on a substrate made of a ternary mixed crystal semiconductor crystal In (x) Ga (1-x) As. In the strained quantum well structure, the strained quantum well structure includes a compressive strained quantum well layer and a barrier layer containing In, Al, Ga, and As.

上記の課題を解決するための第３の発明に係る半導体変調器は、第１の発明において、前記歪量子井戸構造は、圧縮歪量子井戸層と、ＩｎまたはＡｌまたはＧａとＡｓを含む障壁層とからなることを特徴とする。   A semiconductor modulator according to a third invention for solving the above-mentioned problems is the semiconductor modulator according to the first invention, wherein the strained quantum well structure includes a compressive strained quantum well layer and a barrier layer including In, Al, Ga, and As. It is characterized by the following.

上記の課題を解決するための第４の発明に係る半導体変調器は、第１乃至第３のいずれかの発明において、前記歪量子井戸構造は、圧縮歪量子井戸層とＩｎＡｌＡｓまたはＡｌＡｓまたはＧａＡｓまたはＡｌＧａＡｓを含む障壁層とからなることを特徴とする。   According to a fourth aspect of the present invention, there is provided a semiconductor modulator according to any one of the first to third aspects, wherein the strain quantum well structure includes a compressive strain quantum well layer and InAlAs, AlAs, GaAs, or And a barrier layer containing AlGaAs.

上記の課題を解決するための第５の発明に係る半導体変調器は、３元混晶の半導体結晶Ｉｎ(ｘ)Ｇａ(１−ｘ)Ａｓからなる基板の上に、光吸収層として形成される歪量子井戸構造において、前記歪量子井戸構造は、圧縮歪量子井戸層と、前記半導体結晶Ｉｎ(ｘ)Ｇａ(１−ｘ)Ａｓと格子整合するＩｎＡｌＡｓを含む障壁層とからなることを特徴とする。   A semiconductor modulator according to a fifth invention for solving the above-described problems is formed as a light absorption layer on a substrate made of a ternary mixed crystal semiconductor crystal In (x) Ga (1-x) As. In the strained quantum well structure, the strained quantum well structure includes a compressive strained quantum well layer and a barrier layer containing InAlAs lattice-matched with the semiconductor crystal In (x) Ga (1-x) As. And

上記の課題を解決するための第６の発明に係る半導体変調器は、第１乃至第５のいずれかの発明において、前記障壁層が前記圧縮歪量子井戸層との界面側にＩｎ(ｚ)Ｇａ(１−ｚ)Ａｓ層を有することを特徴とする。   A semiconductor modulator according to a sixth invention for solving the above-described problem is the semiconductor modulator according to any one of the first to fifth inventions, wherein the barrier layer is In (z) on the interface side with the compressive strain quantum well layer. It has a Ga (1-z) As layer.

上記の課題を解決するための第７の発明に係る半導体変調器は、第１乃至第６のいずれかの発明において、半導体結晶Ｉｎ(ｘ)Ｇａ(１−ｘ)Ａｓからなる前記基板の組成比ｘは、０＜ｘ≦０．２の範囲にあることを特徴とする。   A semiconductor modulator according to a seventh invention for solving the above-mentioned problems is the composition of the substrate comprising the semiconductor crystal In (x) Ga (1-x) As in any one of the first to sixth inventions. The ratio x is in the range of 0 <x ≦ 0.2.

上記の課題を解決するための第８の発明に係る半導体変調器は、第１乃至第７のいずれかの発明において、前記歪量子井戸構造による吸収波長が１．１〜１．６μｍであることを特徴とする。   A semiconductor modulator according to an eighth aspect of the invention for solving the above-mentioned problems is that, in any one of the first to seventh aspects, the absorption wavelength by the strain quantum well structure is 1.1 to 1.6 μm. It is characterized by.

上記の課題を解決するための第９の発明に係る半導体変調器は、第１乃至第８のいずれかの発明において、前記圧縮歪量子井戸層の材料が、ＩｎＧａＡｓ、ＧａＩｎNＡｓ、ＡｌＧａＩｎＡｓ、ＩｎＧａＡｓＰのいずれかであることを特徴とする。   A semiconductor modulator according to a ninth invention for solving the above-mentioned problems is any one of the first to eighth inventions, wherein the material of the compressive strain quantum well layer is any one of InGaAs, GaInNAs, AlGaInAs, and InGaAsP. It is characterized by.

上記の課題を解決するための第１０の発明に係る半導体変調器は、第１乃至第９のいずれかの発明において、前記歪量子井戸構造がメサストライプ状に加工されており前記歪量子井戸構造の両側を半導体結晶により埋め込まれたことを特徴とする。   A semiconductor modulator according to a tenth aspect of the present invention for solving the above-described problems is the strained quantum well structure according to any one of the first to ninth aspects, wherein the strained quantum well structure is processed in a mesa stripe shape. Both sides of the semiconductor device are embedded with a semiconductor crystal.

上記の課題を解決するための第１１の発明に係る半導体変調器は、第１乃至第１０のいずれかの発明において、前記歪量子井戸構造の両側を埋め込む半導体結晶がＲｕドープ半絶縁性半導体結晶であることを特徴とする。   A semiconductor modulator according to an eleventh aspect of the present invention for solving the above-described problem is the semiconductor modulator according to any one of the first to tenth aspects, wherein the semiconductor crystal embedded on both sides of the strained quantum well structure is a Ru-doped semi-insulating semiconductor crystal. It is characterized by being.

上記の課題を解決するための第の発明に係る光半導体装置は、第１乃至第１のいずれかの発明に係る半導体変調器と同一基板上に半導体レーザが集積されたことを特徴とする。   An optical semiconductor device according to a second invention for solving the above-mentioned problems is characterized in that a semiconductor laser is integrated on the same substrate as the semiconductor modulator according to any one of the first to first inventions.

上述した本発明に係る半導体変調器及び光半導体装置によれば、広い環境温度範囲で安定した動作を実現できる。   According to the above-described semiconductor modulator and optical semiconductor device according to the present invention, stable operation can be realized in a wide environmental temperature range.

本発明の実施形態を説明する。本発明の実施形態は、３元混晶の半導体結晶Ｉｎ(ｘ)Ｇａ(１−ｘ)Ａｓからなる基板上に半導体変調器としての電界吸収型（ＥＡ）光変調器を作製するものである。   An embodiment of the present invention will be described. In the embodiment of the present invention, an electroabsorption (EA) optical modulator as a semiconductor modulator is manufactured on a substrate made of a ternary mixed crystal semiconductor crystal In (x) Ga (1-x) As. .

以下の実施例において、ＩｎＰとは格子定数の異なるＩｎＧａＡｓ３元基板上に歪量子井戸構造を形成し、電界吸収型変調器に適用した例を説明する。   In the following embodiments, an example in which a strained quantum well structure is formed on an InGaAs ternary substrate having a lattice constant different from that of InP and applied to an electroabsorption modulator will be described.

図１乃至図３に基づいて本発明の第１の実施例を詳細に説明する。図１は本実施例に係る半導体変調器の光の伝播方向に直交する断面図、図２はＧａＡｓ及びＩｎＧａＡｓ基板上歪量子井戸の波長と歪の関係を示すグラフ、図３はＩｎ組成０．１のＩｎＧａＡｓ量子井戸からのフォトルミネッセンススペクトルの歪量依存性を示すグラフである。   The first embodiment of the present invention will be described in detail with reference to FIGS. 1 is a cross-sectional view orthogonal to the light propagation direction of the semiconductor modulator according to the present embodiment, FIG. 2 is a graph showing the relationship between the wavelength and strain of strain quantum wells on GaAs and InGaAs substrates, and FIG. It is a graph which shows the distortion amount dependence of the photo-luminescence spectrum from 1 InGaAs quantum well.

本実施例は、３元混晶の半導体結晶ＩｎＧａＡｓ基板上に、波長１．３μｍ帯の電界吸収型光変調器を作製するものである。光吸収領域の障壁層としては、基板に格子整合するＩｎ0.1Ａｌ0.9Ａｓを用い、歪補償無しの構造とする。結晶成長は有機金属気相成長法（ＭＯＶＰＥ法）を用いて行う。層構造を図１に示す。成長温度７００℃、成長圧力７６Torrにおいて、Ｉｎ組成０．１であるｎ−Ｉｎ0.1Ｇａ0.9Ａｓ基板１上にＳｉをドープしたｎ−Ｉｎ0.1Ｇａ0.9Ａｓバッファー層を成長する。さらにＳｉを５ｘ１０17(ｃｍ-3)ドープしたｎ−Ｉｎ0.58Ｇａ0.42Ｐクラッド層２を１．５μｍの厚さに成長し、その上に光吸収層構造を成長する。 In this embodiment, an electroabsorption optical modulator having a wavelength band of 1.3 μm is fabricated on a ternary mixed crystal semiconductor crystal InGaAs substrate. As the barrier layer in the light absorption region, In 0.1 Al 0.9 As lattice-matched to the substrate is used, and the structure has no distortion compensation. Crystal growth is performed using metal organic vapor phase epitaxy (MOVPE method). The layer structure is shown in FIG. An n-In 0.1 Ga 0.9 As buffer layer doped with Si is grown on the n-In 0.1 Ga 0.9 As substrate 1 having an In composition of 0.1 at a growth temperature of 700 ° C. and a growth pressure of 76 Torr. Further, an n-In 0.58 Ga 0.42 P clad layer 2 doped with 5 × 10 17 (cm −3 ) of Si is grown to a thickness of 1.5 μm, and a light absorption layer structure is grown thereon.

ここで、Ｉｎ組成０．１のＩｎＧａＡｓ基板上に圧縮歪となるＩｎＧａＡｓ量子井戸を成長する場合、バンドギャップ波長と量子井戸の圧縮歪量の関係は図２のようになる。Ｉｎ組成０．１の基板上で１．３μｍ帯の変調器を形成するには２％以上の歪がかかるため、５００℃程度の低い温度で成長する。また、Ｉｎ組成０．４５及び０．５のＩｎＧａＡｓ量子井戸層を低温成長し、フォトルミネッセンススペクトルを測定すると図３のようになり、それぞれピーク波長は１．２６μｍ、１．３１μｍが得られ１．３μｍ帯の光吸収層として用いることができることを確認した。   Here, in the case where an InGaAs quantum well having compressive strain is grown on an InGaAs substrate having an In composition of 0.1, the relationship between the band gap wavelength and the amount of compressive strain in the quantum well is as shown in FIG. Since a strain of 2% or more is required to form a 1.3 μm band modulator on a substrate having an In composition of 0.1, it grows at a temperature as low as about 500 ° C. Further, when an InGaAs quantum well layer having In compositions of 0.45 and 0.5 is grown at a low temperature and a photoluminescence spectrum is measured, the peak wavelength is 1.26 μm and 1.31 μm, respectively, as shown in FIG. It was confirmed that it can be used as a light absorption layer in the 3 μm band.

本実施例においては、光吸収層構造は、Ｉｎ組成が０．４５であって、波長１．３μｍの光の吸収係数を制御するのに最適な離調量を持った吸収波長を有するＩｎ0.45Ｇａ0.55Ａｓ圧縮歪量子井戸層の両側に、Ｉｎ組成が０．１であって、基板に格子整合するＩｎ0.1Ａｌ0.9Ａｓ障壁層を配したＩｎＧａＡｓ／ＩｎＡｌＡｓ歪量子井戸構造３とした。ＩｎＧａＡｓ圧縮歪量子井戸層は厚さ７ｎｍ、ＩｎＡｌＡｓ障壁層は厚さ１０ｎｍとした。ＩｎＧａＡｓ／ＩｎＡｌＡｓ歪量子井戸構造３は、６層のＩｎＧａＡｓ圧縮歪量子井戸層と、７層のＩｎＡｌＡｓ障壁層とを交互に設けた６層量子井戸光吸収層である。 In this example, the light absorption layer structure has an In composition of 0.45 and an In 0.45 having an absorption wavelength having an optimum detuning amount for controlling the absorption coefficient of light having a wavelength of 1.3 μm. An InGaAs / InAlAs strained quantum well structure 3 in which an In 0.1 Al 0.9 As barrier layer having an In composition of 0.1 and lattice-matched to the substrate is disposed on both sides of the Ga 0.55 As compressive strain quantum well layer. The InGaAs compressive strain quantum well layer was 7 nm thick, and the InAlAs barrier layer was 10 nm thick. The InGaAs / InAlAs strained quantum well structure 3 is a six-layer quantum well light absorption layer in which six InGaAs compressive strain quantum well layers and seven InAlAs barrier layers are alternately provided.

図１に戻り説明を続けると、歪量子井戸構造３の上に、亜鉛を５ｘ１０17(ｃｍ-3)ドープしたｐ−Ｉｎ0.58Ｇａ0.42Ｐクラッド層４を１．５μｍの厚さに成長し、その上にｐ型に２ｘ１０19(ｃｍ-3)ドープした厚さ１００ｎｍのＩｎ0.1Ｇａ0.9Ａｓコンタクト層５を成長する。 Returning to FIG. 1 and continuing the description, a p-In 0.58 Ga 0.42 P clad layer 4 doped with 5 × 10 17 (cm −3 ) zinc is grown on the strained quantum well structure 3 to a thickness of 1.5 μm. On top of this, a 100 nm thick In 0.1 Ga 0.9 As contact layer 5 doped with 2 × 10 19 (cm −3 ) in a p-type is grown.

このコンタクト層５の上にスパッタリングでＳｉO2層を堆積し、さらにフォトリソグラフィによって幅２μｍ程度のストライプ状のマスクを形成する。このマスクを用いてドライエッチングおよびウェットエッチングにより幅２μｍ、高さ３μｍのメサストライプを形成する。このメサストライプの両脇をポリイミドで埋め込んでポリイミド埋め込み層６とし、基板１を研磨後に上下にそれぞれｐ電極７、ｎ電極８を形成し、リッジ構造へ加工し、波長１．３μｍの光を制御する電界吸収型光変調器を作製した。 A SiO 2 layer is deposited on the contact layer 5 by sputtering, and a striped mask having a width of about 2 μm is formed by photolithography. Using this mask, a mesa stripe having a width of 2 μm and a height of 3 μm is formed by dry etching and wet etching. Both sides of this mesa stripe are embedded with polyimide to form a polyimide embedded layer 6, and after polishing the substrate 1, a p-electrode 7 and an n-electrode 8 are formed on the upper and lower sides, respectively, processed into a ridge structure, and light having a wavelength of 1.3 μm is controlled. An electroabsorption optical modulator was fabricated.

本実施例によれば、電界吸収型光変調器は、室温において消光比は２Ｖ変化時に２０dＢ以上の消光比が得られた。また８５℃の高温下においても１５dＢ以上の消光比が得られ、広い環境温度範囲において変動が小さく、安定した動作を実現した。   According to this example, the electroabsorption optical modulator had an extinction ratio of 20 dB or more when the extinction ratio changed by 2 V at room temperature. In addition, an extinction ratio of 15 dB or more was obtained even at a high temperature of 85 ° C., and the fluctuation was small and a stable operation was realized in a wide environmental temperature range.

図４に基づいて、本発明の第２の実施例を詳細に説明する。図４は、本実施例に係る半導体変調器の光の伝播方向に直交する断面図である。   A second embodiment of the present invention will be described in detail based on FIG. FIG. 4 is a cross-sectional view orthogonal to the light propagation direction of the semiconductor modulator according to this embodiment.

実施例１では光吸収領域の障壁層として基板に格子整合するＩｎ0.1Ａｌ0.9Ａｓを用いて電界吸収型光変調器を作製したが、本実施例は、光吸収領域の障壁層として、基板に対して引張り歪となるＡｌＡｓを用いて歪補償バリア構造とした、波長１．３μｍ帯の電界吸収型光変調器を作製するものである。これにより、高歪の量子井戸層を用いた場合に、平均歪を低減させる効果があり、結晶性の向上が期待できる。また、ＡｌＡｓを用いることで、エネルギーバンドギャップを大きくすることができ、量子井戸と障壁層の間でより大きなバンドオフセットを持たせることができ、キャリア閉じ込め効果を増大させることができる。 In Example 1, an electroabsorption optical modulator was manufactured using In 0.1 Al 0.9 As lattice-matched to the substrate as a barrier layer in the light absorption region. However, in this example, the barrier layer in the light absorption region was formed on the substrate. On the other hand, an electroabsorption optical modulator with a wavelength of 1.3 μm band, which has a strain compensation barrier structure using AlAs that becomes tensile strain, is produced. Thereby, when a high strain quantum well layer is used, there is an effect of reducing the average strain, and an improvement in crystallinity can be expected. Also, by using AlAs, the energy band gap can be increased, a larger band offset can be provided between the quantum well and the barrier layer, and the carrier confinement effect can be increased.

以下、図１に示し上述した部材と同一の部材については、同一符号を付して重複する説明は適宜省略する。   Hereinafter, the same members as those shown in FIG. 1 are described with the same reference numerals, and redundant description will be appropriately omitted.

本実施例に係る半導体変調器の作製方法を以下に述べる。図４に示すように、ｎ−Ｉｎ0.1Ｇａ0.9Ａｓ基板１上にＳｉをドープしたｎ−Ｉｎ0.1Ｇａ0.9Ａｓバッファー層を成長し、さらにＳｉを５ｘ１０17(ｃｍ-3)ドープしたｎ−Ｉｎ0.58Ｇａ0.42Ｐクラッド層２を１．５μｍの厚さに成長し、その上に光吸収層構造を成長する。 A method for manufacturing the semiconductor modulator according to this example will be described below. As shown in FIG. 4, an n-In 0.1 Ga 0.9 As buffer layer doped with Si is grown on an n-In 0.1 Ga 0.9 As substrate 1, and n-In doped with 5 × 10 17 (cm −3 ) of Si. A 0.58 Ga 0.42 P clad layer 2 is grown to a thickness of 1.5 μm, and a light absorption layer structure is grown thereon.

光吸収層は、ＩｎＧａＡｓ圧縮歪量子井戸層の両側に、引張り歪となるＡｌＡｓ障壁層を配したＩｎＧａＡｓ／ＡｌＡｓ歪量子井戸構造２３である。ＡｌＡｓ歪補償層は厚さが１０ｎｍである。ＩｎＧａＡｓ／ＡｌＡｓ歪量子井戸構造２３は、８つのＩｎＧａＡｓ圧縮歪量子井戸層と、９つの引張り歪となるＡｌＡｓ障壁層を交互に設けた８層量子井戸光吸収層である。圧縮歪量子井戸層にはＩｎ0.4Ｇａ0.6Ａｓを用い、厚さは１０ｎｍとする。 The light absorption layer is an InGaAs / AlAs strain quantum well structure 23 in which an AlAs barrier layer that becomes tensile strain is disposed on both sides of the InGaAs compression strain quantum well layer. The AlAs strain compensation layer has a thickness of 10 nm. The InGaAs / AlAs strain quantum well structure 23 is an eight-layer quantum well light absorption layer in which eight InGaAs compression strain quantum well layers and nine AlAs barrier layers that become tensile strain are alternately provided. In 0.4 Ga 0.6 As is used for the compressive strain quantum well layer, and the thickness is 10 nm.

更に、歪量子井戸構造２３の上に亜鉛を５ｘ１０17(ｃｍ-3)ドープしたｐ−Ｉｎ0.58Ｇａ0.42Ｐクラッド層４を１．５μｍの厚さに成長し、その上にｐ型に２ｘ１０19(ｃｍ-3)ドープした厚さ１００ｎｍのＩｎ0.1Ｇａ0.9Ａｓコンタクト層５を成長する。この成長後のウェハをリッジ型へ加工することにより、波長１．３μｍの光を制御する電界吸収型光変調器を作製した。 Further, a p-In 0.58 Ga 0.42 P cladding layer 4 doped with 5 × 10 17 (cm −3 ) of zinc is grown on the strained quantum well structure 23 to a thickness of 1.5 μm, and 2 × 10 19 in p-type is formed thereon. An In 0.1 Ga 0.9 As contact layer 5 having a thickness of 100 nm and doped with (cm −3 ) is grown. The grown wafer was processed into a ridge type to produce an electroabsorption optical modulator that controls light having a wavelength of 1.3 μm.

本実施例によれば、電界吸収型光変調器は、室温において消光比は２Ｖ変化時に２０dＢ以上の消光比が得られた。また８５℃の高温下においても１５dＢ以上の消光比が得られ、広い環境温度範囲において変動が小さく、安定した動作を実現した。   According to this example, the electroabsorption optical modulator had an extinction ratio of 20 dB or more when the extinction ratio changed by 2 V at room temperature. In addition, an extinction ratio of 15 dB or more was obtained even at a high temperature of 85 ° C., and the fluctuation was small and a stable operation was realized in a wide environmental temperature range.

この実施例の変調器では伝導帯と価電子帯のバンドオフセット比が６．５：３．５であり、またＡｌＡｓとＩｎＧａＡｓのバンドギャップ差が大きいという特徴があり、伝導帯のバンドオフセットは７３０ｍｅＶと大きな値となる。これによりキャリア閉じ込めを十分に確保することが可能となり、駆動電圧の低減と、環境温度にも左右されにくい変調器を実現した。   In the modulator of this embodiment, the band offset ratio between the conduction band and the valence band is 6.5: 3.5, and the band gap difference between AlAs and InGaAs is large. The band offset of the conduction band is 730 meV. And a large value. As a result, sufficient carrier confinement can be secured, and a modulator that is less susceptible to the environmental temperature and a drive voltage reduction has been realized.

本実施例のように、基板に対して、圧縮歪となる量子井戸において、障壁層の全部または一部に、基板に対して格子定数の小さい引張り歪のＧａＡｓまたはＡｌＡｓ層を導入することにより、歪補償構造になり、歪による転位の発生が緩和される。また高歪量子井戸成長には低温成長が必要であるが、そのような条件においても２元結晶は３元で見られるような相分離が原理的に生じないため、結晶性は向上できる。さらに３元混晶に変えて、２元のＧａＡｓまたはＡｌＡｓ層を用いることで最も温度が上昇する活性層での基板の垂直方向、面内方向への熱伝導性を向上させる効果も生じる。そのため、半導体変調器の光吸収層温度の上昇が抑えられ、高温環境下でも安定した動作を実現することが可能となる。   By introducing a GaAs or AlAs layer having a small lattice constant with respect to the substrate into the whole or a part of the barrier layer in the quantum well that becomes compressive strain with respect to the substrate as in this embodiment, A distortion compensation structure is formed, and the occurrence of dislocation due to strain is alleviated. Further, low-temperature growth is necessary for high strain quantum well growth, but even under such conditions, the phase separation as seen in the ternary does not occur in the binary crystal, so that the crystallinity can be improved. Further, by using a binary GaAs or AlAs layer instead of the ternary mixed crystal, an effect of improving the thermal conductivity in the vertical direction and the in-plane direction of the substrate in the active layer where the temperature rises most is produced. Therefore, the rise of the light absorption layer temperature of the semiconductor modulator can be suppressed, and stable operation can be realized even in a high temperature environment.

図５に基づいて、本発明の第３の実施例を詳細に説明する。図５は、本実施例に係る半導体変調器の光の伝播方向に直交する断面図である。   A third embodiment of the present invention will be described in detail based on FIG. FIG. 5 is a cross-sectional view orthogonal to the light propagation direction of the semiconductor modulator according to the present embodiment.

実施例１、２ではＩｎ組成０．１のＩｎＧａＡｓ基板を用いて波長１．３μｍ帯用の電界吸収型光変調器を作製する例を説明したが、本実施例では基板のＩｎ組成を高め、１．５５μｍ帯用の電界吸収型光変調器の作製を可能とした例について説明する。   In Examples 1 and 2, an example in which an electro-absorption optical modulator for a wavelength of 1.3 μm band was manufactured using an InGaAs substrate having an In composition of 0.1 was described. In this example, the In composition of the substrate was increased, An example in which an electroabsorption optical modulator for a 1.55 μm band can be manufactured will be described.

以下、図１に示し上述した部材と同一の部材には、同一符号を付して重複する説明は適宜省略する。   In the following, the same members as those shown in FIG.

本実施例に係る半導体変調器の作製方法を以下に述べる。図５に示すように、ｎ−Ｉｎ0.3Ｇａ0.7Ａｓ基板３１上にＳｉをドープしたｎ−Ｉｎ0.3Ｇａ0.7Ａｓバッファー層を成長し、さらにＳｉを５ｘ１０17(ｃｍ-3)ドープしたｎ−Ｉｎ0.78Ｇａ0.22Ｐクラッド層３２を１．５μｍの厚さに成長し、その上に光吸収層構造を成長する。 A method for manufacturing the semiconductor modulator according to this example will be described below. As shown in FIG. 5, an n-In 0.3 Ga 0.7 As buffer layer doped with Si is grown on an n-In 0.3 Ga 0.7 As substrate 31 and further Si is doped with 5 × 10 17 (cm −3 ). A 0.78 Ga 0.22 P cladding layer 32 is grown to a thickness of 1.5 μm, and a light absorption layer structure is grown thereon.

光吸収層は、ＩｎＧａＡｓ圧縮歪量子井戸層の両側に、引張り歪となるＩｎＡｌＡｓ障壁層を配したＩｎＧａＡｓ／ＩｎＡｌＡｓ歪量子井戸構造３３である。ＩｎＡｌＡｓ歪補償層は厚さが１０ｎｍである。ＩｎＧａＡｓ／ＩｎＡｌＡｓ歪量子井戸構造３３は、６層のＩｎＧａＡｓ圧縮歪量子井戸層と、７層のＩｎＡｌＡｓ障壁層を交互に設けた６層量子井戸光吸収層である。ＩｎＧａＡｓ圧縮歪量子井戸層にはＩｎ0.6Ｇａ0.4Ａｓを用い、厚さは１０ｎｍとする。 The light absorption layer is an InGaAs / InAlAs strained quantum well structure 33 in which an InAlAs barrier layer that becomes tensile strain is disposed on both sides of the InGaAs compression strained quantum well layer. The InAlAs strain compensation layer has a thickness of 10 nm. The InGaAs / InAlAs strain quantum well structure 33 is a six-layer quantum well light absorption layer in which six InGaAs compression strain quantum well layers and seven InAlAs barrier layers are alternately provided. In 0.6 Ga 0.4 As is used for the InGaAs compressive strain quantum well layer, and the thickness is 10 nm.

更に、歪量子井戸構造３３の上に亜鉛を５ｘ１０17(ｃｍ-3)ドープしたｐ−Ｉｎ0.78Ｇａ0.22Ｐクラッド層３４を１．５μｍの厚さに成長し、その上にｐ型に２ｘ１０19(ｃｍ-3)ドープした厚さ１００ｎｍのＩｎ0.3Ｇａ0.7Ａｓコンタクト層３５を成長する。この成長後のウェハをリッジ型へ加工することにより、波長１．５５μｍの光を制御する電界吸収型光変調器を作製した。 Further, a p-In 0.78 Ga 0.22 P clad layer 34 doped with 5 × 10 17 (cm −3 ) of zinc is grown on the strained quantum well structure 33 to a thickness of 1.5 μm, and 2 × 10 19 in p-type is formed thereon. An In 0.3 Ga 0.7 As contact layer 35 having a thickness of 100 nm and doped with (cm −3 ) is grown. The grown wafer was processed into a ridge type to produce an electroabsorption optical modulator that controls light having a wavelength of 1.55 μm.

本実施例によれば、電界吸収型光変調器は、室温において消光比は２Ｖ変化時に１０dＢ以上の消光比が得られた。   According to this example, the electroabsorption optical modulator had an extinction ratio of 10 dB or more when the extinction ratio changed by 2 V at room temperature.

図６に基づいて本発明の第４の実施例を詳細に説明する。図６は、本実施例に係る光半導体装置の導波路方向に沿った断面図である。   A fourth embodiment of the present invention will be described in detail based on FIG. FIG. 6 is a cross-sectional view along the waveguide direction of the optical semiconductor device according to this example.

実施例１乃至実施例３では電界吸収型光変調器についての例を述べたが、本実施例では、半導体変調器を半導体レーザと同一基板上に集積した光半導体装置、より詳しくは、電界吸収型光変調器と分布帰還型半導体レーザ（ＤＦＢ−LＤ）をモノリシック集積したＥＡ−ＤＦＢレーザについて説明する。   In the first to third embodiments, an example of an electroabsorption optical modulator has been described. However, in this embodiment, an optical semiconductor device in which a semiconductor modulator is integrated on the same substrate as a semiconductor laser, more specifically, electroabsorption. An EA-DFB laser in which a monolithic integrated optical modulator and distributed feedback semiconductor laser (DFB-LD) are described.

図６に示すように、本実施例に係る光半導体装置は、電界吸収型光変調器９と分布帰還型半導体レーザ１０とを同一基板上にモノリシック集積したものである。以下に、本実施例に係る光半導体装置の作製方法を説明する。   As shown in FIG. 6, the optical semiconductor device according to this embodiment is obtained by monolithically integrating an electroabsorption optical modulator 9 and a distributed feedback semiconductor laser 10 on the same substrate. A method for manufacturing the optical semiconductor device according to this example will be described below.

まず、分布帰還型半導体レーザ１０部分の構成を説明する。ｎ−Ｉｎ0.1Ｇａ0.9Ａｓ基板１上にＳｉをドープしたｎ−Ｉｎ0.1Ｇａ0.9Ａｓバッファー層を成長し、さらにＳｉを５ｘ１０17(ｃｍ-3)ドープしたｎ−Ｉｎ0.58Ｇａ0.42ｐクラッド層１１を１．５μｍの厚さに成長し、その上に４０ｎｍの厚さのノンドープのＩｎＧａＡｓＰガイド層１２を導入する。その上に活性層構造を成長する。 First, the configuration of the distributed feedback semiconductor laser 10 will be described. An n-In 0.1 Ga 0.9 As buffer layer doped with Si is grown on the n-In 0.1 Ga 0.9 As substrate 1, and further an n-In 0.58 Ga 0.42 p cladding layer 11 doped with 5 × 10 17 (cm −3 ) of Si. Is grown to a thickness of 1.5 μm, and a 40 nm thick non-doped InGaAsP guide layer 12 is introduced thereon. An active layer structure is grown thereon.

活性層は、ＩｎＧａＡｓ圧縮歪量子井戸層の両側に、引張り歪となるＧａＡｓ障壁層を配したＩｎＧａＡｓ／ＧａＡｓ歪量子井戸構造１３である。ＧａＡｓ歪補償層は厚さが１５ｎｍである。ＩｎＧａＡｓ／ＧａＡｓ歪量子井戸構造１３は、３層のＩｎＧａＡｓ圧縮歪量子井戸層と、４層のＧａＡｓ障壁層とを交互に設けた３層量子井戸活性層である。ＩｎＧａＡｓ圧縮歪量子井戸層は、波長１．３μｍで発振させるためＩｎ0.5Ｇａ0.5Ａｓを用い、厚さは１０ｎｍとした。 The active layer is an InGaAs / GaAs strained quantum well structure 13 in which a GaAs barrier layer that becomes tensile strain is disposed on both sides of the InGaAs compression strained quantum well layer. The GaAs strain compensation layer has a thickness of 15 nm. The InGaAs / GaAs strained quantum well structure 13 is a three-layer quantum well active layer in which three InGaAs compressive strain quantum well layers and four GaAs barrier layers are alternately provided. The InGaAs compressive strain quantum well layer was made of In 0.5 Ga 0.5 As and had a thickness of 10 nm for oscillation at a wavelength of 1.3 μm.

そして、歪量子井戸構造１３の上に４０ｎｍの厚さのノンドープのＩｎＧａＡｓＰガイド層１４を成長し、回折格子を形成し、その上をＩｎＧａＰクラッド層１５で埋め込む。   Then, a 40 nm-thick non-doped InGaAsP guide layer 14 is grown on the strained quantum well structure 13 to form a diffraction grating, and the InGaP cladding layer 15 is buried thereon.

上述した分布帰還型半導体レーザ１０部分と後述する変調器９部分を結合させるためには、バットジョイント技術を用いる。具体的には、レーザ構造成長層の上にスパッタリングでＳｉO2マスクをつけ、ウェットエッチングにより量子井戸活性層を幅１５μｍ、長さ４００μｍの島形状に形成する。即ち、幅１５μｍ、長さ４００μｍの領域のみに量子井戸活性層を残した状態とする。その状態で変調器構造を成長することにより、レーザのメサ部分の周りに変調器構造が成長され、集積化される。 In order to couple the distributed feedback semiconductor laser 10 described above and the modulator 9 described later, a butt joint technique is used. Specifically, a SiO 2 mask is attached on the laser structure growth layer by sputtering, and the quantum well active layer is formed into an island shape having a width of 15 μm and a length of 400 μm by wet etching. That is, the quantum well active layer is left only in the region having a width of 15 μm and a length of 400 μm. By growing the modulator structure in that state, the modulator structure is grown and integrated around the mesa portion of the laser.

電界吸収型光変調器９部分の構成は、ＩｎＧａＡｓ圧縮歪量子井戸層の両側に、引張り歪となるＡｌ0.8Ｇａ0.2Ａｓ障壁層を配したＩｎＧａＡｓ／ＡｌＧａＡｓ歪量子井戸構造４３である。Ａｌ0.8Ｇａ0.2Ａｓ歪補償層は厚さが１０ｎｍである。歪量子井戸構造４３は、６層のＩｎＧａＡｓ圧縮歪量子井戸層と７層のＡｌ0.8Ｇａ0.2Ａｓ障壁層を交互に設けた６層量子井戸光吸収層である。量子井戸層は波長１．３μｍの光の吸収係数を制御するのに最適な離調量を持った吸収波長をもつ組成であるＩｎ0.4Ｇａ0.6Ａｓを用い、厚さは１０ｎｍとした。 The configuration of the electroabsorption optical modulator 9 portion is an InGaAs / AlGaAs strained quantum well structure 43 in which an Al 0.8 Ga 0.2 As barrier layer that becomes tensile strain is disposed on both sides of the InGaAs compressive strain quantum well layer. The Al 0.8 Ga 0.2 As strain compensation layer has a thickness of 10 nm. The strain quantum well structure 43 is a six-layer quantum well light absorption layer in which six InGaAs compression strain quantum well layers and seven Al 0.8 Ga 0.2 As barrier layers are alternately provided. The quantum well layer was made of In 0.4 Ga 0.6 As, which has a composition with an absorption wavelength having an optimum detuning amount for controlling the absorption coefficient of light having a wavelength of 1.3 μm, and its thickness was 10 nm.

バットジョイント成長の後に、マスクを除去し、再度ＳｉO2を堆積し、フォトリソグラフィ技術によりストライプ状のマスクを新しく形成する。これをマスクとしてＲＩＥ(反応性イオンエッチング)により、幅２μｍで高さ１．６μｍ程度のメサストライプを形成した。引き続き、メサストライプの両側の基板１上に、ＭＯＶＰＥ法により電流ブロック層として、ＲｕドープのＩｎＧａＰ層を層厚３μｍ成長させた。Ｒｕの原料として、ビスエチルシクロペンタディエニルルテニウム（bis(ethylcycloPentadienyl)ruthenium(II)）を用いた。 After the butt joint growth, the mask is removed, SiO 2 is deposited again, and a striped mask is newly formed by photolithography. Using this as a mask, mesa stripes having a width of 2 μm and a height of about 1.6 μm were formed by RIE (reactive ion etching). Subsequently, a Ru-doped InGaP layer was grown to a thickness of 3 μm as a current blocking layer on the substrate 1 on both sides of the mesa stripe by the MOVPE method. Bisethylcyclopentadienyl ruthenium (II) was used as a raw material for Ru.

更に、ＳｉO2からなるマスクをHＦにより除去し、層厚１．５μｍでZｎドーピング濃度が５ｘ１０17(ｃｍ-3)であるｐ−Ｉｎ0.58Ｇａ0.42Ｐオーバークラッド層４，１５を成長した。その上にｐ型に２ｘ１０19(ｃｍ-3)ドープした厚さ１００ｎｍのＩｎ0.1Ｇａ0.9Ａｓコンタクト層５を成長した。なお、電気的な絶縁を行うため、レーザ部１０と変調器部９の間のＩｎＧａＡｓコンタクト層は除去する。基板１を研磨後に上下にそれぞれｐ電極７、ｎ電極８を形成する。 Further, the SiO 2 mask was removed by HF, and p-In 0.58 Ga 0.42 P overclad layers 4 and 15 having a layer thickness of 1.5 μm and a Zn doping concentration of 5 × 10 17 (cm −3 ) were grown. A 100 nm thick In 0.1 Ga 0.9 As contact layer 5 doped with 2 × 10 19 (cm −3 ) p-type was grown thereon. Note that the InGaAs contact layer between the laser unit 10 and the modulator unit 9 is removed for electrical insulation. After the substrate 1 is polished, a p-electrode 7 and an n-electrode 8 are formed above and below, respectively.

本実施例によれば、ＥＡ−ＤＦＢレーザは閾値電流１８ｍＡ、特性温度９０K、消光比は２０dＢ以上で高温下においても、レーザの閾値電流の変動が小さく、安定した動作を実現した。   According to the present embodiment, the EA-DFB laser has a threshold current of 18 mA, a characteristic temperature of 90 K, an extinction ratio of 20 dB or more, and the laser threshold current does not fluctuate even at high temperatures, thereby realizing stable operation.

以上全ての実施例において、電界吸収型光変調器およびレーザの量子井戸には上記のＩｎＧａＡｓの他に、ＧａＩｎNＡｓやＩｎＧａＡｓＰ、ＩｎＧａＡｌＡｓなどを用いることができる。   In all the embodiments described above, GaInNAs, InGaAsP, InGaAlAs or the like can be used in addition to the above InGaAs for the electroabsorption optical modulator and the quantum well of the laser.

また、障壁層においては、基板であるＩｎＧａＡｓのＩｎ組成が０．１の時に障壁層としてＧａＡｓを用いる場合にＧａＡｓの引っ張り歪の歪量は０．７%程度であり、基板であるＩｎＧａＡｓのＩｎ組成が０．２の時に障壁層としてＧａＡｓを用いる場合にＧａＡｓの引っ張り歪の歪量は１．５%程度であり、障壁層としては歪量が１．５%以下である場合が有効である。   Further, in the barrier layer, when GaAs is used as the barrier layer when the In composition of the InGaAs substrate is 0.1, the strain amount of the tensile strain of GaAs is about 0.7%. When GaAs is used as the barrier layer when the composition is 0.2, the strain amount of tensile strain of GaAs is about 1.5%, and the barrier layer is effective when the strain amount is 1.5% or less. .

更に、障壁層の材料は上記の他に、ＩｎまたはＡｌまたはＧａと、Ａｓとを含むもの、例えば、ＧａＡｓ，ＡｌＧａＡｓ，ＩｎＧａＡｌＡｓ，ＧａNＡｓ，ＧａＩｎNＡｓ，ＧａＡｓＰなどを用いることができる。   In addition to the above, the material of the barrier layer may include In, Al or Ga, and As, for example, GaAs, AlGaAs, InGaAlAs, GaNAs, GaInNAs, GaAsP, or the like.

また、障壁層が、量子井戸層との界面側にＩｎ(ｚ)Ｇａ(１−ｚ)Ａｓ層を有するようにしてもよい。例えば、図７に示すように、障壁層を基板に対して引張り歪となるＩｎＧａＡｓ／ＧａＡｓ歪補償障壁層とし、厚さ１０ｎｍのＩｎＧａＡｓ量子井戸層の両側に厚さ５ｎｍのＩｎ0.1Ｇａ0.9Ａｓ障壁層を配し、更に厚さ１５ｎｍのＧａＡｓ歪補償障壁層を配す構成とする、換言すると、Ｉｎ0.1Ｇａ0.9Ａｓ障壁層を、量子井戸層とＧａＡｓ歪補償障壁層の間に配するようにしてもよい。 The barrier layer may have an In (z) Ga (1-z) As layer on the interface side with the quantum well layer. For example, as shown in FIG. 7, the barrier layer is an InGaAs / GaAs strain compensation barrier layer that becomes tensile strain with respect to the substrate, and an In 0.1 Ga 0.9 As barrier with a thickness of 5 nm on both sides of an InGaAs quantum well layer with a thickness of 10 nm. In other words, an In 0.1 Ga 0.9 As barrier layer is arranged between the quantum well layer and the GaAs strain compensation barrier layer. May be.

このように、障壁層が、量子井戸層との界面側にＩｎ(ｚ)Ｇａ(１−ｚ)Ａｓ層を有する構成とすれば、ＩｎＧａＡｓ３元基板上圧縮歪量子井戸において、障壁層またはその一部に、基板に対して格子定数の小さい引っ張り歪層（例えば、ＧａＡｓ層）を導入することにより歪補償構造になり、量子井戸を多層化した際の歪による転位、欠陥の発生が緩和される。
さらに結晶的に安定した２元結晶は３元、４元の材料で問題となる相分離などが無いため、結晶性向上が可能となる。
また３元材料に比べ熱抵抗が低いため、放熱性が向上し、素子全体の発熱を抑えた高温度特性動作が可能となる。 As described above, when the barrier layer has an In (z) Ga (1-z) As layer on the interface side with the quantum well layer, the barrier layer or one of the barrier layers in the compressive strain quantum well on the InGaAs ternary substrate is used. By introducing a tensile strained layer (for example, a GaAs layer) having a small lattice constant into the substrate, a strain compensation structure is obtained, and the generation of dislocations and defects due to strain when the quantum well is multilayered is mitigated. .
Furthermore, since the crystal stable binary crystal does not have a phase separation which is a problem with ternary and quaternary materials, crystallinity can be improved.
In addition, since the thermal resistance is lower than that of the ternary material, heat dissipation is improved, and high temperature characteristic operation with reduced heat generation of the entire element is possible.

ＩｎＧａＡｓ／ＧａＡｓ障壁層におけるＩｎＧａＡｓ（Ｉｎ(ｚ)Ｇａ(１−ｚ)Ａｓ）はなくてもよく、ＧａＡｓのみからなるものであってよい。また、ＩｎＧａＡｓ／ＧａＡｓ障壁層におけるＩｎＧａＡｓの層厚は５ｎｍでなくてもよく、ＧａＡｓ層の層厚も１５ｎｍでなくてもよい。また、障壁層におけるＩｎＧａＡｓのＩｎ組成は０より大きく量子井戸層のＩｎＧａＡｓのＩｎ組成未満であることが望ましい。但し、ＧａＡｓの層厚が厚すぎる場合、ＩｎＧａＡｓ層のＩｎ組成が小さく層厚が厚すぎる場合等に障壁層の引張り歪が大きすぎると結晶が劣化する。
また、ＩｎＧａＡｓ／ＧａＡｓ障壁層においてＧａＡｓに若干量のＩｎが含まれた場合、例えば、ＩｎＧａＡｓ／ＧａＡｓ障壁層におけるＧａＡｓをＩｎ組成ｙが０より大きく０．０５以下であるＩｎ(ｙ)Ｇａ(１−ｙ)Ａｓに代えた場合でも同様の効果を奏する。 InGaAs (In (z) Ga (1-z) As) in the InGaAs / GaAs barrier layer may not be present, and may be composed only of GaAs. In addition, the InGaAs / GaAs barrier layer may have a thickness of InGaAs that is not 5 nm, and the thickness of the GaAs layer may not be 15 nm. In addition, the In composition of InGaAs in the barrier layer is preferably greater than 0 and less than the In composition of InGaAs in the quantum well layer. However, if the thickness of the GaAs layer is too large, or if the In composition of the InGaAs layer is small and the layer thickness is too thick, etc., if the tensile strain of the barrier layer is too large, the crystal deteriorates.
Further, when the InGaAs / GaAs barrier layer contains a small amount of In, for example, In (y) Ga (1) in which GaAs in the InGaAs / GaAs barrier layer has an In composition y greater than 0 and less than or equal to 0.05. -Y) Even if it replaces with As, there exists the same effect.

また、クラッド層に用いる材料としては、上述したＩｎＧａＰのほかに、大きなバンドギャップを有するＩｎＡｌＡｓ、ＩｎＧａＡｌＡｓ、ＩｎＡｌＰ、ＩｎＧａＡｌＰなどを用いることも可能である。   In addition to the above-described InGaP, InAlAs, InGaAlAs, InAlP, InGaAlP, or the like having a large band gap can also be used as the material used for the cladding layer.

また上述した実施例ではリッジを絶縁体のポリイミドで埋め込んだが、ＢＣＢでの埋め込みやＦｅやＲｕをドーピングしたＩｎＧａＰやＩｎＡｌＡｓなどの半絶縁の半導体で埋め込むこともできる。   In the above-described embodiments, the ridge is buried with an insulating polyimide, but it can be buried with BCB or a semi-insulating semiconductor such as InGaP or InAlAs doped with Fe or Ru.

また、半導体結晶Ｉｎ(ｘ)Ｇａ(１−ｘ)Ａｓからなる基板１の組成比ｘは、０＜ｘ≦０．２の範囲にあればよい。   The composition ratio x of the substrate 1 made of the semiconductor crystal In (x) Ga (1-x) As may be in the range of 0 <x ≦ 0.2.

さらに、歪量子井戸構造によって吸収係数を制御される光の波長が１．１〜１．６μｍであれば、上述した実施例を良好に適用することができる。   Furthermore, if the wavelength of the light whose absorption coefficient is controlled by the strained quantum well structure is 1.1 to 1.6 μm, the above-described embodiments can be favorably applied.

本発明は、半導体変調器における光吸収特性を向上するため、歪量子井戸構造の高品質化を実現する技術であって、広い環境温度範囲で安定して動作する光半導体装置に適用可能である。   INDUSTRIAL APPLICABILITY The present invention is a technique for realizing a high quality strained quantum well structure in order to improve light absorption characteristics in a semiconductor modulator, and can be applied to an optical semiconductor device that operates stably in a wide environmental temperature range. .

本発明の実施例１に係る半導体変調器の断面図である。It is sectional drawing of the semiconductor modulator which concerns on Example 1 of this invention. ＧａＡｓ及びＩｎＧａＡｓ基板上歪量子井戸の波長と歪の関係を示すグラフである。It is a graph which shows the relationship between the wavelength of a strain quantum well on a GaAs and InGaAs substrate, and distortion. Ｉｎ組成０．１のＩｎＧａＡｓ基板上のＩｎＧａＡｓ量子井戸からのフォトルミネッセンススペクトルの歪量依存性を示すグラフである。It is a graph which shows the distortion amount dependence of the photoluminescence spectrum from the InGaAs quantum well on the InGaAs substrate of In composition 0.1. 本発明の実施例２に係る半導体変調器の断面図である。It is sectional drawing of the semiconductor modulator which concerns on Example 2 of this invention. 本発明の実施例３に係る半導体変調器の断面図である。It is sectional drawing of the semiconductor modulator which concerns on Example 3 of this invention. 本発明の実施例４に係る光半導体装置の断面図である。It is sectional drawing of the optical semiconductor device which concerns on Example 4 of this invention. 本発明の他の例に係る量子井戸活性層のＩｎ組成変化を示す説明図である。It is explanatory drawing which shows In composition change of the quantum well active layer based on the other example of this invention. ＩｎＧａＡｓ３元混晶の熱抵抗のＩｎ組成依存性を示す特性図である。It is a characteristic view which shows In composition dependence of the thermal resistance of an InGaAs ternary mixed crystal.

符号の説明Explanation of symbols

１ ｎ−Ｉｎ0.1Ｇａ0.9Ａｓ基板
２，１１ ｎ−Ｉｎ0.58Ｇａ0.42Ｐクラッド層
３ Ｉｎ0.45Ｇａ0.55Ａｓ／Ｉｎ0.1Ａｌ0.9Ａｓ量子井戸構造
４，１５ ｐ−Ｉｎ0.58Ｇａ0.42Ｐクラッド層
５ Ｉｎ0.1Ｇａ0.9Ａｓコンタクト層
６ ポリイミド
７ ｐ電極
８ ｎ電極
９ 電界吸収型光変調器
１０ 分布帰還型半導体レーザ
１２，１４ ＩｎＧａＡｓＰガイド層
１３ Ｉｎ0.5Ｇａ0.5Ａｓ／ＧａＡｓ量子井戸構造
２３ Ｉｎ0.4Ｇａ0.6Ａｓ／ＡｌＡｓ量子井戸構造
３１ ｎ−Ｉｎ0.3Ｇａ0.7Ａｓ基板
３２ ｎ−Ｉｎ0.78Ｇａ0.22Ｐクラッド層
３３ Ｉｎ0.6Ｇａ0.4Ａｓ／ＩｎＡｌＡｓ量子井戸構造
３４ ｐ−Ｉｎ0.78Ｇａ0.22Ｐクラッド層
３５ Ｉｎ0.3Ｇａ0.7Ａｓコンタクト層
４３ Ｉｎ0.4Ｇａ0.6Ａｓ／Ａｌ0.8Ｇａ0.2Ａｓ量子井戸構造 1 n-In 0.1 Ga 0.9 As substrate 2,11 n-In 0.58 Ga 0.42 P clad layer 3 In 0.45 Ga 0.55 As / In 0.1 Al 0.9 As quantum well structure 4,15 p-In 0.58 Ga 0.42 P clad layer 5 In 0.1 Ga 0.9 As contact layer 6 polyimide 7 p electrode 8 n electrode 9 electroabsorption optical modulator 10 distributed feedback semiconductor laser 12, 14 InGaAsP guide layer 13 In 0.5 Ga 0.5 As / GaAs quantum well structure 23 In 0.4 Ga 0.6 As / AlAs quantum well structure 31 n-In 0.3 Ga 0.7 As substrate 32 n-In 0.78 Ga 0.22 P cladding layer 33 In 0.6 Ga 0.4 As / InAlAs quantum well structure 34 p-In 0.78 Ga 0.22 P cladding layer 35 In 0.3 Ga 0.7 As contact layer 43 In 0.4 Ga 0.6 As / Al 0.8 Ga 0.2 As quantum well structure

Claims (12)

３元混晶の半導体結晶Ｉｎ(ｘ)Ｇａ(１−ｘ)Ａｓからなる基板の上に、光吸収層として形成される歪量子井戸構造において、
前記歪量子井戸構造は、圧縮歪量子井戸層と、歪量が０より大きく１．５％以下である引っ張り歪障壁層とからなることを特徴とする半導体変調器。 In a strained quantum well structure formed as a light absorption layer on a substrate made of a ternary mixed crystal semiconductor crystal In (x) Ga (1-x) As,
The strained quantum well structure comprises a compressive strained quantum well layer and a tensile strained barrier layer having an amount of strain greater than 0 and not more than 1.5%. ３元混晶の半導体結晶Ｉｎ(ｘ)Ｇａ(１−ｘ)Ａｓからなる基板の上に、光吸収層として形成される歪量子井戸構造において、
前記歪量子井戸構造は、圧縮歪量子井戸層と、ＩｎまたはＡｌまたはＧａとＡｓを含む障壁層とからなることを特徴とする半導体変調器。 In a strained quantum well structure formed as a light absorption layer on a substrate made of a ternary mixed crystal semiconductor crystal In (x) Ga (1-x) As,
The strained quantum well structure comprises a compressive strained quantum well layer and a barrier layer containing In or Al or Ga and As. 前記歪量子井戸構造は、圧縮歪量子井戸層と、ＩｎまたはＡｌまたはＧａとＡｓを含む障壁層とからなることを特徴とする請求項１の半導体変調器。   2. The semiconductor modulator according to claim 1, wherein the strain quantum well structure includes a compressive strain quantum well layer and a barrier layer containing In, Al, Ga, and As. 前記歪量子井戸構造は、圧縮歪量子井戸層とＩｎＡｌＡｓまたはＡｌＡｓまたはＧａＡｓまたはＡｌＧａＡｓを含む障壁層とからなることを特徴とする請求項１乃至請求項３の半導体変調器。   4. The semiconductor modulator according to claim 1, wherein the strain quantum well structure includes a compressive strain quantum well layer and a barrier layer containing InAlAs, AlAs, GaAs, or AlGaAs. ３元混晶の半導体結晶Ｉｎ(ｘ)Ｇａ(１−ｘ)Ａｓからなる基板の上に、光吸収層として形成される歪量子井戸構造において、
前記歪量子井戸構造は、圧縮歪量子井戸層と、前記半導体結晶Ｉｎ(ｘ)Ｇａ(１−ｘ)Ａｓと格子整合するＩｎＡｌＡｓを含む障壁層とからなることを特徴とする半導体変調器。 In a strained quantum well structure formed as a light absorption layer on a substrate made of a ternary mixed crystal semiconductor crystal In (x) Ga (1-x) As,
The strained quantum well structure includes a compressive strained quantum well layer and a barrier layer containing InAlAs lattice-matched with the semiconductor crystal In (x) Ga (1-x) As. 前記障壁層が前記圧縮歪量子井戸層との界面側にＩｎ(ｚ)Ｇａ(１−ｚ)Ａｓ層を有することを特徴とする請求項１乃至請求項５の半導体変調器。   6. The semiconductor modulator according to claim 1, wherein the barrier layer has an In (z) Ga (1-z) As layer on an interface side with the compressive strain quantum well layer. 前記半導体結晶Ｉｎ(ｘ)Ｇａ(１−ｘ)Ａｓからなる前記基板の組成比ｘは、０＜ｘ≦０．２の範囲にあることを特徴とする請求項１乃至請求項６の何れか一項の半導体変調器。   7. The composition ratio x of the substrate made of the semiconductor crystal In (x) Ga (1-x) As is in a range of 0 <x ≦ 0.2. A semiconductor modulator according to one item. 前記歪量子井戸構造による吸収波長が１．１〜１．６μｍであることを特徴とする請求項１乃至請求項７の何れか一項の半導体変調器。   8. The semiconductor modulator according to claim 1, wherein an absorption wavelength by the strain quantum well structure is 1.1 to 1.6 [mu] m. 前記圧縮歪量子井戸層の材料が、ＩｎＧａＡｓ、ＧａＩｎNＡｓ、ＡｌＧａＩｎＡｓ、ＩｎＧａＡｓＰのいずれかであることを特徴とする請求項１乃至請求項８の何れか一項の半導体変調器。   9. The semiconductor modulator according to claim 1, wherein the material of the compressive strain quantum well layer is any one of InGaAs, GaInNAs, AlGaInAs, and InGaAsP. 前記歪量子井戸構造がメサストライプ状に加工されており前記歪量子井戸構造の両側を半導体結晶により埋め込まれたことを特徴とする請求項１乃至請求項９の何れか一項の半導体変調器。   10. The semiconductor modulator according to claim 1, wherein the strain quantum well structure is processed in a mesa stripe shape, and both sides of the strain quantum well structure are embedded with a semiconductor crystal. 前記歪量子井戸構造の両側を埋め込む半導体結晶がＲｕドープ半絶縁性半導体結晶であることを特徴とする請求項１乃至請求項１０の何れか一項の半導体変調器。   11. The semiconductor modulator according to claim 1, wherein the semiconductor crystal filling both sides of the strained quantum well structure is a Ru-doped semi-insulating semiconductor crystal. 請求項１乃至請求項１１の何れか一項に記載の半導体変調器と同一基板上に、半導体レーザが集積されたことを特徴とする光半導体装置。   12. An optical semiconductor device, wherein a semiconductor laser is integrated on the same substrate as the semiconductor modulator according to any one of claims 1 to 11.
JP2007048977A 2007-02-28 2007-02-28 Semiconductor modulator Expired - Fee Related JP5062732B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2007048977A JP5062732B2 (en) 2007-02-28 2007-02-28 Semiconductor modulator

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2007048977A JP5062732B2 (en) 2007-02-28 2007-02-28 Semiconductor modulator

Publications (2)

Publication Number Publication Date
JP2008209863A true JP2008209863A (en) 2008-09-11
JP5062732B2 JP5062732B2 (en) 2012-10-31

Family

ID=39786184

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2007048977A Expired - Fee Related JP5062732B2 (en) 2007-02-28 2007-02-28 Semiconductor modulator

Country Status (1)

Country Link
JP (1) JP5062732B2 (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2008300735A (en) * 2007-06-01 2008-12-11 Sumitomo Electric Ind Ltd Method for manufacturing iii-v compound semiconductor optical element
JP2012002929A (en) * 2010-06-15 2012-01-05 Opnext Japan Inc Method for manufacturing semiconductor optical element, laser module, and optical transmission apparatus
JP2013246343A (en) * 2012-05-28 2013-12-09 Mitsubishi Electric Corp Semiconductor optical modulator
CN103928558A (en) * 2014-04-17 2014-07-16 吉林大学 Double-color all-optical switch based on quantum well inter-subband transition cavity-induced coherence effect

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH04372188A (en) * 1991-06-20 1992-12-25 Furukawa Electric Co Ltd:The Semiconductor laser element
JP2002043696A (en) * 2000-07-26 2002-02-08 Fujitsu Ltd Semiconductor laser device
JP2003060310A (en) * 2001-08-21 2003-02-28 Nippon Telegr & Teleph Corp <Ntt> Semiconductor optical element and manufacturing method therefor
JP2007066930A (en) * 2005-08-29 2007-03-15 Nippon Telegr & Teleph Corp <Ntt> Optical semiconductor device

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH04372188A (en) * 1991-06-20 1992-12-25 Furukawa Electric Co Ltd:The Semiconductor laser element
JP2002043696A (en) * 2000-07-26 2002-02-08 Fujitsu Ltd Semiconductor laser device
JP2003060310A (en) * 2001-08-21 2003-02-28 Nippon Telegr & Teleph Corp <Ntt> Semiconductor optical element and manufacturing method therefor
JP2007066930A (en) * 2005-08-29 2007-03-15 Nippon Telegr & Teleph Corp <Ntt> Optical semiconductor device

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2008300735A (en) * 2007-06-01 2008-12-11 Sumitomo Electric Ind Ltd Method for manufacturing iii-v compound semiconductor optical element
JP2012002929A (en) * 2010-06-15 2012-01-05 Opnext Japan Inc Method for manufacturing semiconductor optical element, laser module, and optical transmission apparatus
JP2013246343A (en) * 2012-05-28 2013-12-09 Mitsubishi Electric Corp Semiconductor optical modulator
CN103928558A (en) * 2014-04-17 2014-07-16 吉林大学 Double-color all-optical switch based on quantum well inter-subband transition cavity-induced coherence effect

Also Published As

Publication number Publication date
JP5062732B2 (en) 2012-10-31

Similar Documents

Publication Publication Date Title
JP4663964B2 (en) Long wavelength photonics device comprising a GaAsSb quantum well layer
JP4922036B2 (en) Quantum dot semiconductor device
JP4792854B2 (en) Semiconductor optical device and manufacturing method thereof
JP2006286809A (en) Optical semiconductor device and its manufacturing method
US9595811B2 (en) Quantum cascade semiconductor laser
JP5475398B2 (en) Semiconductor light emitting device
JP5062732B2 (en) Semiconductor modulator
JP4998238B2 (en) Integrated semiconductor optical device
JP2014045083A (en) Semiconductor optical element and semiconductor optical element manufacturing method
KR20120123116A (en) Semiconductor device
JP4641230B2 (en) Optical semiconductor device
JP2008211142A (en) Optical semiconductor device
JP4045639B2 (en) Semiconductor laser and semiconductor light emitting device
JP2008235519A (en) Optical semiconductor element and optical semiconductor element manufacturing method
JPH07297485A (en) Semiconductor laser device and manufacture thereof
JP2009260093A (en) Optical semiconductor device
WO2019208697A1 (en) Optical semiconductor element and method for producing same, and integrated optical semiconductor element and method for producing same
JP2010062401A (en) Semiconductor structure and optical semiconductor element using the same
JP7210876B2 (en) optical device
JP2018006590A (en) Optical semiconductor element
JP4072938B2 (en) Semiconductor optical device and manufacturing method thereof
JP2010062400A (en) Optical semiconductor element
JP2009059919A (en) Optical semiconductor device and method of manufacturing the same
JP2007103581A (en) Embedded semiconductor laser
JP4983791B2 (en) Optical semiconductor element

Legal Events

Date Code Title Description
A621 Written request for application examination

Free format text: JAPANESE INTERMEDIATE CODE: A621

Effective date: 20081117

A521 Written amendment

Free format text: JAPANESE INTERMEDIATE CODE: A821

Effective date: 20081117

A977 Report on retrieval

Free format text: JAPANESE INTERMEDIATE CODE: A971007

Effective date: 20110823

A131 Notification of reasons for refusal

Free format text: JAPANESE INTERMEDIATE CODE: A131

Effective date: 20110906

A521 Written amendment

Free format text: JAPANESE INTERMEDIATE CODE: A523

Effective date: 20111102

TRDD Decision of grant or rejection written
A01 Written decision to grant a patent or to grant a registration (utility model)

Free format text: JAPANESE INTERMEDIATE CODE: A01

Effective date: 20120731

A01 Written decision to grant a patent or to grant a registration (utility model)

Free format text: JAPANESE INTERMEDIATE CODE: A01

A61 First payment of annual fees (during grant procedure)

Free format text: JAPANESE INTERMEDIATE CODE: A61

Effective date: 20120802

R150 Certificate of patent or registration of utility model

Free format text: JAPANESE INTERMEDIATE CODE: R150

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20150817

Year of fee payment: 3

S531 Written request for registration of change of domicile

Free format text: JAPANESE INTERMEDIATE CODE: R313531

R350 Written notification of registration of transfer

Free format text: JAPANESE INTERMEDIATE CODE: R350

S533 Written request for registration of change of name

Free format text: JAPANESE INTERMEDIATE CODE: R313533

R350 Written notification of registration of transfer

Free format text: JAPANESE INTERMEDIATE CODE: R350

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

LAPS Cancellation because of no payment of annual fees