JP6981492B2 - Manufacturing method of semiconductor laser device - Google Patents

Manufacturing method of semiconductor laser device Download PDF

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JP6981492B2
JP6981492B2 JP2020036620A JP2020036620A JP6981492B2 JP 6981492 B2 JP6981492 B2 JP 6981492B2 JP 2020036620 A JP2020036620 A JP 2020036620A JP 2020036620 A JP2020036620 A JP 2020036620A JP 6981492 B2 JP6981492 B2 JP 6981492B2
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仁 佐久間
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Mitsubishi Electric Corp
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この開示は、半導体レーザ装置の製造方法に関する。 This disclosure relates to a method of manufacturing a semiconductor laser device.

半導体レーザ装置は、大容量データを通信するための超高速かつ高効率な光ネットワークのキーデバイスとなっており、その信頼性はますます重要になってきている。例えば通信用のリッジ型半導体レーザ装置では、活性層の近傍に絶縁膜が配置されている。これはリッジとその両側との屈折率差を利用して光を導波路に閉じ込めるためである。活性層で発生した光は絶縁膜まで染み出し、一部が絶縁膜上の電極にまで漏れて、吸収され、効率が低下する。これを防ぐには絶縁膜を厚くすればよいが、そうすると活性層に印加されるストレスが増大し、特性の変化又は結晶欠陥が発生する。また、絶縁膜をプラズマで形成すると、活性層にダメージを与えるため信頼性を確保できない問題があった。 Semiconductor laser devices have become key devices for ultra-high-speed and highly efficient optical networks for communicating large volumes of data, and their reliability is becoming more and more important. For example, in a ridge type semiconductor laser device for communication, an insulating film is arranged in the vicinity of the active layer. This is because the light is confined in the waveguide by utilizing the difference in refractive index between the ridge and both sides thereof. The light generated in the active layer seeps out to the insulating film, and a part of the light leaks to the electrodes on the insulating film and is absorbed, resulting in a decrease in efficiency. To prevent this, the insulating film may be thickened, but this increases the stress applied to the active layer, resulting in changes in characteristics or crystal defects. Further, when the insulating film is formed by plasma, there is a problem that reliability cannot be ensured because the active layer is damaged.

特許文献１では、上記のような問題を解決するために絶縁膜を２層構造とし、第１層目として成膜温度６００℃前後の熱ＣＶＤ法により膜厚５０ｎｍのＳｉＮ膜を形成し、第２層目として成膜温度３００℃前後のプラズマＣＶＤ法により、膜厚１００ｎｍのＳｉＮ膜を形成している。特許文献１には、第２層目のＳｉＮ膜の成膜温度を第１層目のＳｉＮ膜の成膜温度よりも低くすることで、第２層目のＳｉＮ膜を厚くしても半導体層に印加されるストレスが低くなるため信頼性を確保できることが記載されている。さらに、特許文献１には、第２層目のＳｉＮ膜のプラズマＣＶＤ法による成膜時に、第１層目のＳｉＮ膜が有るため、プラズマが半導体層に直接に当たらず、プラズマダメージによる信頼性の低下を防ぐこともできることも記載されている。 In Patent Document 1, in order to solve the above problems, the insulating film has a two-layer structure, and a SiN film having a film thickness of 50 nm is formed as the first layer by a thermal CVD method having a film thickness of around 600 ° C. As the second layer, a SiN film having a film thickness of 100 nm is formed by a plasma CVD method having a film formation temperature of about 300 ° C. According to Patent Document 1, the film formation temperature of the SiN film of the second layer is lower than the film formation temperature of the SiN film of the first layer, so that even if the SiN film of the second layer is thickened, the semiconductor layer is formed. It is described that reliability can be ensured because the stress applied to the film is reduced. Further, in Patent Document 1, since the first layer SiN film is present at the time of film formation of the second layer SiN film by the plasma CVD method, the plasma does not directly hit the semiconductor layer, and the reliability due to plasma damage is obtained. It is also stated that it is possible to prevent the decrease in plasma.

特開２０１０−１６２８１号公報Japanese Unexamined Patent Publication No. 2010-16281

例えばＩｎＰ系の通信用半導体レーザでは、熱ＣＶＤのような６００℃前後の高温成膜によって絶縁膜を形成すると、半導体材料が熱分解してしまう問題があった。 For example, in an InP-based communication semiconductor laser, there is a problem that the semiconductor material is thermally decomposed when an insulating film is formed by high-temperature film formation at around 600 ° C. such as thermal CVD.

本開示は上述の問題を解決するためになされたものであり、活性層へのストレス及びダメージを低減させて信頼性を向上させることができる半導体レーザ装置の製造方法を提供することを目的とする。 The present disclosure has been made to solve the above-mentioned problems, and an object of the present disclosure is to provide a method for manufacturing a semiconductor laser device capable of reducing stress and damage to an active layer and improving reliability. ..

本願の開示にかかる半導体レーザ装置の製造方法は、ＩｎＰ基板の上に、下部クラッド層、活性層及び上部クラッド層が積層した積層構造に対しドライエッチングを施すことで左右に該積層構造のいずれかの層の表面が露出したメサストライプ構造を形成することと、該メサストライプ構造の側面と、該メサストライプ構造の左右の該メサストライプ構造より低い低地部分とに、ＡＬＤ法で第１絶縁膜を形成することと、スパッタ法で該第１絶縁膜の上に該第１絶縁膜より厚い第２絶縁膜を形成することと、該メサストライプ構造の上面に第１電極を形成し、該ＩｎＰ基板の裏面に第２電極を形成することと、を備え、前記メサストライプ構造は垂直メサであることを特徴とする。 The method for manufacturing a semiconductor laser apparatus according to the present disclosure is one of the laminated structures on the left and right by performing dry etching on a laminated structure in which a lower clad layer, an active layer and an upper clad layer are laminated on an InP substrate. The first insulating film is formed by the ALD method on the side surface of the mesa stripe structure and the low-lying portion lower than the mesa stripe structure on the left and right of the mesa stripe structure to form the mesa stripe structure in which the surface of the layer is exposed. The InP substrate is formed by forming a second insulating film thicker than the first insulating film on the first insulating film by a sputtering method, and forming a first electrode on the upper surface of the mesa stripe structure. The mesa stripe structure is characterized by forming a second electrode on the back surface of the above, and the mesa stripe structure is a vertical mesa.

本開示のその他の特徴は以下に明らかにする。 Other features of this disclosure are clarified below.

この開示によれば、例えば、最初にスパッタ法で第１絶縁膜を形成し、その後、第１絶縁膜を形成したときよりも高い成膜温度のプラズマＣＶＤ法で第１絶縁膜の上に第１絶縁膜より薄い第２絶縁膜を形成することで、活性層へのストレス及びダメージを低減させて半導体レーザ装置の信頼性を向上させることができる。 According to this disclosure, for example, a first insulating film is first formed by a sputtering method, and then a plasma CVD method having a higher film formation temperature than when the first insulating film is formed is used on the first insulating film. By forming the second insulating film thinner than the first insulating film, the stress and damage to the active layer can be reduced and the reliability of the semiconductor laser apparatus can be improved.

実施の形態１、２に係る半導体レーザ装置の断面図である。It is sectional drawing of the semiconductor laser apparatus which concerns on Embodiments 1 and 2. 製造途中の半導体レーザ装置の断面図である。It is sectional drawing of the semiconductor laser apparatus in the middle of manufacturing. 製造途中の半導体レーザ装置の断面図である。It is sectional drawing of the semiconductor laser apparatus in the middle of manufacturing. 製造途中の半導体レーザ装置の断面図である。It is sectional drawing of the semiconductor laser apparatus in the middle of manufacturing. 実施の形態３に係る製造途中の半導体レーザ装置の断面図である。It is sectional drawing of the semiconductor laser apparatus in the process of manufacturing which concerns on Embodiment 3. FIG. 実施の形態３に係る半導体レーザ装置の断面図である。It is sectional drawing of the semiconductor laser apparatus which concerns on Embodiment 3. FIG.

実施の形態に係る半導体レーザ装置の製造方法と半導体レーザ装置について図面を参照して説明する。同じ又は対応する構成要素には同じ符号を付し、説明の繰り返しを省略する場合がある。 A method for manufacturing a semiconductor laser device and a semiconductor laser device according to an embodiment will be described with reference to the drawings. The same or corresponding components may be designated by the same reference numerals and the description may be omitted.

実施の形態１．
図１は、実施の形態１に係る半導体レーザ装置の断面図である。この半導体レーザ装置はｎ型のＩｎＰで形成されたＩｎＰ基板１１を備えている。ＩｎＰ基板１１の上にはｎ型の下部クラッド層１２が形成されている。下部クラッド層１２の上には活性層１３が形成されている。活性層１３の上にはｐ型の第１上部クラッド層１４とｐ型の第２上部クラッド層１５がこの順に形成されている。第１上部クラッド層１４と第２上部クラッド層１５は、別々に形成された２つの層である。しかし、形状を維持しつつこれらの層を１つの層に集約してもよい。第２上部クラッド層１５の上には、ｐ型のコンタクト層１６が形成されている。 Embodiment 1.
FIG. 1 is a cross-sectional view of the semiconductor laser device according to the first embodiment. This semiconductor laser device includes an InP substrate 11 formed of n-type InP. An n-type lower clad layer 12 is formed on the InP substrate 11. An active layer 13 is formed on the lower clad layer 12. A p-type first upper clad layer 14 and a p-type second upper clad layer 15 are formed on the active layer 13 in this order. The first upper clad layer 14 and the second upper clad layer 15 are two layers formed separately. However, these layers may be combined into one layer while maintaining the shape. A p-type contact layer 16 is formed on the second upper clad layer 15.

このように、ＩｎＰ基板１１の上に、下部クラッド層１２、活性層１３、第１第２上部クラッド層１４、１５及びコンタクト層１６が積層した積層構造が形成されている。この積層構造は、メサストライプ構造を有する形状で形成されている。図１の例では、第１上部クラッド層１４の上に、第２上部クラッド層１５とコンタクト層１６を有するメサストライプ構造が形成されている。積層構造の中でどの層をメサストライプ構造にするかは任意である。例えば、積層構造を構成する全ての層でメサストライプ構造を形成してもよい。この積層構造は、例えばＧａＩｎＡｓＰ系の半導体材料で形成することができる。 As described above, a laminated structure in which the lower clad layer 12, the active layer 13, the first and second upper clad layers 14, 15 and the contact layer 16 are laminated is formed on the InP substrate 11. This laminated structure is formed in a shape having a mesa stripe structure. In the example of FIG. 1, a mesa stripe structure having a second upper clad layer 15 and a contact layer 16 is formed on the first upper clad layer 14. Which layer of the laminated structure has the mesa stripe structure is arbitrary. For example, a mesa stripe structure may be formed by all the layers constituting the laminated structure. This laminated structure can be formed of, for example, a GaInAsP-based semiconductor material.

積層構造の上に第１絶縁膜１７と第２絶縁膜１８の２層の絶縁膜が形成されている。第１絶縁膜１７と第２絶縁膜１８は、コンタクト層１６の上面を露出させつつ、メサストライプ構造を覆う。第１絶縁膜１７と第２絶縁膜１８から露出したコンタクト層１６には第１電極１９が形成されている。第１電極１９はｐ側電極として機能する。ＩｎＰ基板１１の裏面には第２電極２０が形成されている。第２電極２０はｎ側電極として機能する。半導体レーザ装置の動作時には、第１電極１９と第２電極２０の間に電圧を印加し、図１の紙面手前方向又は紙面奥行き方向にレーザ光を放出させる。 Two layers of an insulating film, a first insulating film 17 and a second insulating film 18, are formed on the laminated structure. The first insulating film 17 and the second insulating film 18 cover the mesa stripe structure while exposing the upper surface of the contact layer 16. A first electrode 19 is formed on the contact layer 16 exposed from the first insulating film 17 and the second insulating film 18. The first electrode 19 functions as a p-side electrode. A second electrode 20 is formed on the back surface of the InP substrate 11. The second electrode 20 functions as an n-side electrode. During operation of the semiconductor laser device, a voltage is applied between the first electrode 19 and the second electrode 20, and the laser beam is emitted in the front direction of the paper surface or the depth direction of the paper surface in FIG.

次に、実施の形態１に係る半導体レーザ装置の製造方法を説明する。まず、ＩｎＰ基板１１の上に、下部クラッド層１２、活性層１３、第１第２上部クラッド層１４、１５及びコンタクト層１６が積層した積層構造を形成する。この積層構造に対しフォトリソグラフィ及びドライエッチングを施すことで、積層構造をメサストライプ構造を有する形状とする。図２は、ＩｎＰ基板１１の上にメサストライプ構造を有する積層構造が形成されたことを示す半導体レーザ装置の断面図である。 Next, a method of manufacturing the semiconductor laser device according to the first embodiment will be described. First, a laminated structure is formed in which the lower clad layer 12, the active layer 13, the first and second upper clad layers 14, 15 and the contact layer 16 are laminated on the InP substrate 11. By performing photolithography and dry etching on this laminated structure, the laminated structure has a shape having a mesa stripe structure. FIG. 2 is a cross-sectional view of a semiconductor laser device showing that a laminated structure having a mesa stripe structure is formed on the InP substrate 11.

次いで、第１絶縁膜１７と第２絶縁膜１８を形成する。図３は、第１絶縁膜１７と第２絶縁膜１８が形成された半導体レーザ装置の断面図である。第１絶縁膜１７は、積層構造の上にスパッタ法で形成する。第１絶縁膜１７の成膜温度は１５０℃前後とすることができる。第１絶縁膜１７の成膜温度は例えば１４０−１６０℃の範囲である。第１絶縁膜１７の膜厚は例えば３００−７００ｎｍである。第１絶縁膜１７の材料は、絶縁膜であれば特に限定されないが、例えば、ＳｉＯ膜などの酸化膜である。 Next, the first insulating film 17 and the second insulating film 18 are formed. FIG. 3 is a cross-sectional view of a semiconductor laser device in which the first insulating film 17 and the second insulating film 18 are formed. The first insulating film 17 is formed on the laminated structure by a sputtering method. The film formation temperature of the first insulating film 17 can be around 150 ° C. The film formation temperature of the first insulating film 17 is, for example, in the range of 140-160 ° C. The film thickness of the first insulating film 17 is, for example, 300-700 nm. The material of the first insulating film 17 is not particularly limited as long as it is an insulating film, but is, for example, an oxide film such as a SiO film.

第２絶縁膜１８は、第１絶縁膜１７を形成したときよりも高い成膜温度のプラズマＣＶＤ法で第１絶縁膜１７の上に形成する。第２絶縁膜１８の成膜温度は３００℃前後とすることができる。第２絶縁膜１８の成膜温度は例えば２９０−３１０℃の範囲である。第２絶縁膜１８は第１絶縁膜１７より薄い。第２絶縁膜１８の膜厚は例えば１００ｎｍ以下である。第２絶縁膜１８の材料は、絶縁膜であれば特に限定されないが、例えば、ＳｉＯ膜などの酸化膜である。 The second insulating film 18 is formed on the first insulating film 17 by a plasma CVD method having a higher film forming temperature than when the first insulating film 17 is formed. The film formation temperature of the second insulating film 18 can be around 300 ° C. The film formation temperature of the second insulating film 18 is, for example, in the range of 290-310 ° C. The second insulating film 18 is thinner than the first insulating film 17. The film thickness of the second insulating film 18 is, for example, 100 nm or less. The material of the second insulating film 18 is not particularly limited as long as it is an insulating film, but is, for example, an oxide film such as a SiO film.

次いで、コンタクト層１６を露出させる。図４は、コンタクト層１６の上面が露出した半導体レーザ装置の断面図である。この工程では、第１絶縁膜１７と第２絶縁膜１８のうち、メサストライプ構造の上に形成された部分を除去して、コンタクト層１６の上面を露出させる。 The contact layer 16 is then exposed. FIG. 4 is a cross-sectional view of a semiconductor laser device in which the upper surface of the contact layer 16 is exposed. In this step, the portion of the first insulating film 17 and the second insulating film 18 formed on the mesa stripe structure is removed to expose the upper surface of the contact layer 16.

次いで、第１電極１９と第２電極２０を形成する。図１は、第１電極１９と第２電極２０が形成された半導体レーザ装置の断面図である。ｐ側電極として機能する第１電極１９は第２上部クラッド層１５の上にコンタクト層１６と接して形成されるとともに、第２絶縁膜１８の全体を覆う。第１電極１９の膜厚は例えば４００ｎｍ−５００ｎｍの範囲とすることができる。第１電極１９の表面にＡｕメッキを形成してもよい。その後、ＩｎＰ基板１１を薄板化し、ＩｎＰ基板１１の裏面に直接又は導電層を介して第２電極２０を形成する。こうして、リッジが形成された半導体層が絶縁膜で覆われたＩｎＰ系の半導体レーザ装置が製造される。この半導体レーザ装置は例えば通信用途に用いることができる。 Next, the first electrode 19 and the second electrode 20 are formed. FIG. 1 is a cross-sectional view of a semiconductor laser device in which a first electrode 19 and a second electrode 20 are formed. The first electrode 19 that functions as the p-side electrode is formed on the second upper clad layer 15 in contact with the contact layer 16 and covers the entire second insulating film 18. The film thickness of the first electrode 19 can be, for example, in the range of 400 nm-500 nm. Au plating may be formed on the surface of the first electrode 19. After that, the InP substrate 11 is thinned, and the second electrode 20 is formed on the back surface of the InP substrate 11 directly or via a conductive layer. In this way, an InP-based semiconductor laser device in which the semiconductor layer on which the ridge is formed is covered with an insulating film is manufactured. This semiconductor laser device can be used, for example, for communication applications.

実施の形態１に係る半導体レーザ装置の製造方法では、第１絶縁膜１７をスパッタ法で形成し、第１絶縁膜１７より薄い第２絶縁膜１８をプラズマＣＶＤ法で形成した。スパッタ法を採用することで、低い成膜温度でストレスの小さい第１絶縁膜１７を形成することができる。他方、成膜温度が高くストレスの大きいプラズマＣＶＤ法で形成される第２絶縁膜１８を第１絶縁膜１７より薄くする。上述の例では、第１絶縁膜１７の膜厚を３００−７００ｎｍとし、第２絶縁膜１８の膜厚を１００ｎｍ以下とした。これにより、第１絶縁膜１７と第２絶縁膜１８を形成することによる活性層１３へのストレスを低減できる。 In the method for manufacturing a semiconductor laser device according to the first embodiment, the first insulating film 17 is formed by a sputtering method, and the second insulating film 18 thinner than the first insulating film 17 is formed by a plasma CVD method. By adopting the sputtering method, the first insulating film 17 with low stress can be formed at a low film formation temperature. On the other hand, the second insulating film 18 formed by the plasma CVD method, which has a high film forming temperature and a large stress, is made thinner than the first insulating film 17. In the above example, the film thickness of the first insulating film 17 is 300-700 nm, and the film thickness of the second insulating film 18 is 100 nm or less. As a result, the stress on the active layer 13 due to the formation of the first insulating film 17 and the second insulating film 18 can be reduced.

また、半導体層である積層構造に接する絶縁膜としてスパッタ法で第１絶縁膜１７を形成することで、第１絶縁膜をプラズマＣＶＤ法で形成する場合と比べて、半導体層へのダメージを低減できる。一方で、スパッタ法ではカバレッジが悪いため、絶縁層を第１絶縁膜だけとしてしまうと、電極と半導体層の接触による特性劣化が起こりえる。そこで、カバレッジのよい成膜方法であるプラズマＣＶＤ法で第２絶縁膜１８を形成することで電極と半導体層の接触を抑制している。そのため、半導体レーザ装置の信頼性を高めることができる。 Further, by forming the first insulating film 17 by the sputtering method as the insulating film in contact with the laminated structure which is the semiconductor layer, the damage to the semiconductor layer is reduced as compared with the case where the first insulating film is formed by the plasma CVD method. can. On the other hand, since the coverage is poor in the sputtering method, if the insulating layer is only the first insulating film, the characteristics may be deteriorated due to the contact between the electrode and the semiconductor layer. Therefore, the contact between the electrode and the semiconductor layer is suppressed by forming the second insulating film 18 by the plasma CVD method, which is a film forming method having good coverage. Therefore, the reliability of the semiconductor laser device can be improved.

実施の形態１に係る半導体レーザ装置の製造方法と半導体レーザ装置は様々な変形が可能である。例えば、半導体レーザ装置の各層の導電型を反転させることができる。コンタクト層１６を省略した積層構造を採用してもよい。実施の形態１で言及した変形は以下の実施の形態に係る半導体レーザ装置の製造方法と半導体レーザ装置にも応用できる。なお、以下の実施の形態に係る半導体レーザ装置の製造方法と半導体レーザ装置は、実施の形態１との共通点が多いので実施の形態１との相違点を中心に説明する。 The method for manufacturing a semiconductor laser device and the semiconductor laser device according to the first embodiment can be variously modified. For example, the conductive type of each layer of the semiconductor laser device can be inverted. A laminated structure in which the contact layer 16 is omitted may be adopted. The modifications mentioned in the first embodiment can be applied to the method for manufacturing a semiconductor laser device and the semiconductor laser device according to the following embodiments. Since the method for manufacturing the semiconductor laser device and the semiconductor laser device according to the following embodiments have much in common with the first embodiment, the differences from the first embodiment will be mainly described.

実施の形態２．
実施の形態２に係る半導体レーザ装置の製造方法では、メサストライプ構造を有する形状で積層構造を形成し、図２の構成を得る点は実施の形態１と同じである。しかしながら、実施の形態２の第１絶縁膜１７は、積層構造の上にＡＬＤ（Ａｔｏｍｉｃ Ｌａｙｅｒ Ｄｅｐｏｓｉｔｉｏｎ）法で形成する。第１絶縁膜１７の成膜温度は１５０℃前後とすることができる。第１絶縁膜１７の成膜温度は例えば１４０−１６０℃の範囲である。第１絶縁膜１７の膜厚は例えば１００ｎｍ以下である。第１絶縁膜１７の材料は、絶縁膜であれば特に限定されないが、例えば、ＳｉＯ膜などの酸化膜である。 Embodiment 2.
The method for manufacturing a semiconductor laser device according to the second embodiment is the same as the first embodiment in that a laminated structure is formed in a shape having a mesa stripe structure and the configuration shown in FIG. 2 is obtained. However, the first insulating film 17 of the second embodiment is formed on the laminated structure by the ALD (Atomic Layer Deposition) method. The film formation temperature of the first insulating film 17 can be around 150 ° C. The film formation temperature of the first insulating film 17 is, for example, in the range of 140-160 ° C. The film thickness of the first insulating film 17 is, for example, 100 nm or less. The material of the first insulating film 17 is not particularly limited as long as it is an insulating film, but is, for example, an oxide film such as a SiO film.

実施の形態２では、スパッタ法で第１絶縁膜１７の上に第１絶縁膜１７より厚い第２絶縁膜１８を形成する。第２絶縁膜１８の成膜温度は１５０℃前後とすることができる。第２絶縁膜１８の成膜温度は例えば１４０−１６０℃の範囲である。第２絶縁膜１８の膜厚は例えば３００−７００ｎｍである。第２絶縁膜１８の材料は、絶縁膜であれば特に限定されないが、例えば、ＳｉＯ膜などの酸化膜である。 In the second embodiment, a second insulating film 18 thicker than the first insulating film 17 is formed on the first insulating film 17 by a sputtering method. The film formation temperature of the second insulating film 18 can be around 150 ° C. The film formation temperature of the second insulating film 18 is, for example, in the range of 140-160 ° C. The film thickness of the second insulating film 18 is, for example, 300-700 nm. The material of the second insulating film 18 is not particularly limited as long as it is an insulating film, but is, for example, an oxide film such as a SiO film.

次いで、図４に示されるように、コンタクト層１６の上の第１絶縁膜１７と第２絶縁膜１８を除去してコンタクト層１６の上面を露出させる。その後、第１電極１９と第２電極２０を形成し、図１の構成を得る点は実施の形態１と同じである。すなわち、第２上部クラッド層１５の上にコンタクト層１６と接するように第１電極１９を形成し、ＩｎＰ基板１１の裏面に直接又は導電層を介して第２電極２０を形成する。 Next, as shown in FIG. 4, the first insulating film 17 and the second insulating film 18 on the contact layer 16 are removed to expose the upper surface of the contact layer 16. After that, the first electrode 19 and the second electrode 20 are formed, and the point of obtaining the configuration of FIG. 1 is the same as that of the first embodiment. That is, the first electrode 19 is formed on the second upper clad layer 15 so as to be in contact with the contact layer 16, and the second electrode 20 is formed directly on the back surface of the InP substrate 11 or via the conductive layer.

実施の形態２に係る半導体レーザ装置の製造方法では、第１絶縁膜１７をＡＬＤ法で形成し、第１絶縁膜１７より厚い第２絶縁膜１８をスパッタ法で形成した。ＡＬＤ法を採用することで、カバレッジ性に優れ、成膜温度が低く、ストレスの小さい第１絶縁膜１７を形成することができる。さらに、スパッタ法を採用することで、成膜温度が低く、ストレスの小さい第２絶縁膜１８を形成することができる。実施の形態２の第１絶縁膜１７と第２絶縁膜１８は、これらが両方ともプラズマＣＶＤ法で形成された膜より低ストレスであるため、活性層１３へのストレス及びダメージを低減させて半導体レーザ装置の信頼性を向上させることができる。また、成膜レートが小さいＡＬＤ法で形成する第１絶縁膜１７を薄くし、成膜レートが大きいスパッタ法で形成する第２絶縁膜１８を第１絶縁膜１７より厚くすることで、成膜に要する時間を短くすることができる。 In the method for manufacturing a semiconductor laser device according to the second embodiment, the first insulating film 17 is formed by the ALD method, and the second insulating film 18 thicker than the first insulating film 17 is formed by the sputtering method. By adopting the ALD method, it is possible to form the first insulating film 17 having excellent coverage, a low film formation temperature, and low stress. Further, by adopting the sputtering method, it is possible to form the second insulating film 18 having a low film forming temperature and low stress. Since both the first insulating film 17 and the second insulating film 18 of the second embodiment have lower stress than the film formed by the plasma CVD method, the stress and damage to the active layer 13 are reduced to reduce the stress and damage to the semiconductor. The reliability of the laser device can be improved. Further, the first insulating film 17 formed by the ALD method having a low film forming rate is thinned, and the second insulating film 18 formed by the sputtering method having a high film forming rate is made thicker than the first insulating film 17 to form a film. The time required for this can be shortened.

実施の形態３．
実施の形態３に係る半導体レーザ装置の製造方法では、メサストライプ構造を有する形状で積層構造を形成し、図２の構成を得る点は実施の形態１と同じである。図２の構成を形成した後に第１絶縁膜１７を形成する。例えば図３の第１絶縁膜１７と同じ形状の第１絶縁膜が形成される。第１絶縁膜１７の成膜方法、成膜温度、膜厚は例えば実施の形態１の第１絶縁膜１７と同じである。 Embodiment 3.
The method for manufacturing a semiconductor laser device according to the third embodiment is the same as the first embodiment in that a laminated structure is formed in a shape having a mesa stripe structure and the configuration shown in FIG. 2 is obtained. After forming the configuration of FIG. 2, the first insulating film 17 is formed. For example, a first insulating film having the same shape as the first insulating film 17 in FIG. 3 is formed. The film forming method, film forming temperature, and film thickness of the first insulating film 17 are, for example, the same as those of the first insulating film 17 of the first embodiment.

この第１絶縁膜１７を形成した後、第２絶縁膜１８を形成する前に、第１絶縁膜の一部をエッチングして第１絶縁膜１７をメサストライプ構造の根元部分に残す。具体的には、第１絶縁膜１７にレジストを形成し、フォトリソグラフィおよびドライエッチング処理により、メサスストライプ構造のボトム近傍のみに第１絶縁膜１７Ａを残す。図５には、エッチングによりメサストライプ構造の根元部分に残った第１絶縁膜１７Ａが示されている。図５の例では、第１絶縁膜１７Ａは、メサストライプ構造の側面下部と、第１上部クラッド層１４の上に残っている。第１絶縁膜１７Ａは、例えばメサストライプ構造の側面上部を避けて、メサストライプ構造の根元部分に形成されている。 After forming the first insulating film 17 and before forming the second insulating film 18, a part of the first insulating film is etched to leave the first insulating film 17 at the root portion of the mesa stripe structure. Specifically, a resist is formed on the first insulating film 17, and the first insulating film 17A is left only in the vicinity of the bottom of the mesas stripe structure by photolithography and dry etching treatment. FIG. 5 shows the first insulating film 17A remaining at the root portion of the mesa stripe structure by etching. In the example of FIG. 5, the first insulating film 17A remains on the lower side surface of the mesa stripe structure and on the first upper clad layer 14. The first insulating film 17A is formed at the root portion of the mesa stripe structure, for example, avoiding the upper side surface of the mesa stripe structure.

こうして、第１絶縁膜１７の一部をエッチングで除去した後に、第２絶縁膜１８を形成する。図５には第２絶縁膜１８が示されている。第２絶縁膜１８は、実施の形態１の第２絶縁膜１８と同じ成膜方法、成膜温度、膜厚で形成することができる。 In this way, after removing a part of the first insulating film 17 by etching, the second insulating film 18 is formed. The second insulating film 18 is shown in FIG. The second insulating film 18 can be formed by the same film forming method, film forming temperature, and film thickness as the second insulating film 18 of the first embodiment.

次いで、メサストライプ構造の上面の第２絶縁膜１８を除去してコンタクト層１６を露出させる。これにより、第２絶縁膜１８は、第１絶縁膜１７と積層構造を、第２上部クラッド層１５の上方を露出させつつ覆う。次いで、ｐ側電極として機能し第２上部クラッド層１５と電気的に接続された第１電極１９をコンタクト層１６と接するように形成する。次いで、ＩｎＰ基板１１を薄板化し、ＩｎＰ基板１１の裏面側に第２電極２０を形成し、図６に示す半導体レーザ装置が製造される。 Next, the second insulating film 18 on the upper surface of the mesa stripe structure is removed to expose the contact layer 16. As a result, the second insulating film 18 covers the first insulating film 17 and the laminated structure while exposing the upper side of the second upper clad layer 15. Next, the first electrode 19 which functions as the p-side electrode and is electrically connected to the second upper clad layer 15 is formed so as to be in contact with the contact layer 16. Next, the InP substrate 11 is thinned to form a second electrode 20 on the back surface side of the InP substrate 11, and the semiconductor laser device shown in FIG. 6 is manufactured.

第１絶縁膜１７Ａはスパッタ膜であるのでカバレッジが不十分となり得る。実施の形態３では、第１絶縁膜１７Ａをメサストライプ構造の根元部分のみに配置している。これにより、カバレッジ性が不十分な第１絶縁膜１７Ａが原因で、電極と半導体層が接触する可能性を低減し、特性劣化を防ぐことができる。また、第２絶縁膜１８はプラズマＣＶＤ法で形成される成膜温度が高くストレスの大きい膜である。そこで、この第２絶縁膜１８を例えば１００ｎｍ以下とすることで第１絶縁膜１７Ａより薄くして、活性層１３へのストレスの印加を低減した。他方、絶縁膜全体で十分な厚さを確保するために、成膜温度が低くストレスの小さいスパッタ膜である第１絶縁膜１７Ａは第２絶縁膜１８より厚くした。スパッタ膜を第１絶縁膜１７Ａとすることで活性層１３へのダメージを低減できる。 Since the first insulating film 17A is a sputtered film, the coverage may be insufficient. In the third embodiment, the first insulating film 17A is arranged only at the root portion of the mesa stripe structure. As a result, the possibility that the electrode and the semiconductor layer come into contact with each other due to the first insulating film 17A having insufficient coverage can be reduced, and deterioration of the characteristics can be prevented. Further, the second insulating film 18 is a film formed by the plasma CVD method and having a high film forming temperature and a large stress. Therefore, the second insulating film 18 was made thinner than the first insulating film 17A by, for example, 100 nm or less, and the application of stress to the active layer 13 was reduced. On the other hand, in order to secure a sufficient thickness in the entire insulating film, the first insulating film 17A, which is a sputter film having a low film formation temperature and low stress, is made thicker than the second insulating film 18. By using the first insulating film 17A as the sputtered film, damage to the active layer 13 can be reduced.

１１ ＩｎＰ基板、 １２ 下部クラッド層、 １３ 活性層、 １４ 第１上部クラッド層、 １５ 第２上部クラッド層、 １６ コンタクト層、 １７ 第１絶縁膜、 １８ 第２絶縁膜、 １９ 第１電極、 ２０ 第２電極 11 InP substrate, 12 lower clad layer, 13 active layer, 14 first upper clad layer, 15 second upper clad layer, 16 contact layer, 17 first insulating film, 18 second insulating film, 19 first electrode, 20th. 2 electrodes

Claims (3)

ＩｎＰ基板の上に、下部クラッド層、活性層及び上部クラッド層が積層した積層構造に対しドライエッチングを施すことで左右に前記積層構造のいずれかの層の表面が露出したメサストライプ構造を形成することと、
前記メサストライプ構造の側面と、前記メサストライプ構造の左右の前記メサストライプ構造より低い低地部分とに、ＡＬＤ法で第１絶縁膜を形成することと、
スパッタ法で前記第１絶縁膜の上に前記第１絶縁膜より厚い第２絶縁膜を形成することと、
前記メサストライプ構造の上面に第１電極を形成し、前記ＩｎＰ基板の裏面に第２電極を形成することと、を備え、
前記メサストライプ構造は垂直メサであることを特徴とする半導体レーザ装置の製造方法。 By performing dry etching on the laminated structure in which the lower clad layer, the active layer and the upper clad layer are laminated on the InP substrate, a mesa stripe structure in which the surface of any of the layers of the laminated structure is exposed is formed on the left and right. That and
The first insulating film is formed by the ALD method on the side surface of the mesa stripe structure and the lowland portion lower than the mesa stripe structure on the left and right sides of the mesa stripe structure.
By forming a second insulating film thicker than the first insulating film on the first insulating film by a sputtering method,
A first electrode is formed on the upper surface of the mesa stripe structure, and a second electrode is formed on the back surface of the InP substrate .
A method for manufacturing a semiconductor laser device, wherein the mesa stripe structure is a vertical mesa. 前記第１絶縁膜と前記第２絶縁膜の成膜温度は１４０−１６０℃であることを特徴とする請求項１に記載の半導体レーザ装置の製造方法。 The method for manufacturing a semiconductor laser device according to claim 1, wherein the film forming temperature of the first insulating film and the second insulating film is 140-160 ° C. 前記第１絶縁膜の膜厚は１００ｎｍ以下であり、前記第２絶縁膜の膜厚は３００−７００ｎｍであることを特徴とする請求項１又は２に記載の半導体レーザ装置の製造方法。 The method for manufacturing a semiconductor laser device according to claim 1 or 2, wherein the film thickness of the first insulating film is 100 nm or less, and the film thickness of the second insulating film is 300 to 700 nm.
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Family Cites Families (28)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH10303179A (en) * 1997-04-25 1998-11-13 Hitachi Ltd Manufacture of semiconductor optical element, semiconductor optical element manufactured by the same, and light applied system
JPH11186219A (en) * 1997-12-17 1999-07-09 Oki Electric Ind Co Ltd Dry etching
JPH11330610A (en) * 1998-05-11 1999-11-30 Nichia Chem Ind Ltd Nitride semiconductor laser
WO2001026193A1 (en) * 1999-10-01 2001-04-12 Corning Lasertron, Inc. Method for making a ridge waveguide semiconductor device
JP4090768B2 (en) * 2002-03-20 2008-05-28 株式会社日立製作所 Semiconductor laser element
JP2003347674A (en) * 2002-05-30 2003-12-05 Mitsubishi Electric Corp Semiconductor laser device and manufacturing method therefor
JP2005085977A (en) * 2003-09-09 2005-03-31 Sharp Corp Semiconductor laser device and manufacturing method of semiconductor laser device
JP4622225B2 (en) * 2003-10-06 2011-02-02 ソニー株式会社 Semiconductor laser device and manufacturing method thereof
JP4640752B2 (en) * 2003-12-05 2011-03-02 シャープ株式会社 Gallium nitride semiconductor laser and manufacturing method thereof
JP4814538B2 (en) * 2004-03-15 2011-11-16 パナソニック株式会社 Semiconductor laser device and manufacturing method thereof
JP2006012899A (en) * 2004-06-22 2006-01-12 Sharp Corp Semiconductor laser device and its manufacturing method
JP2006086218A (en) * 2004-09-14 2006-03-30 Sharp Corp Ridge type semiconductor laser device and its manufacturing method
JP2006324427A (en) * 2005-05-18 2006-11-30 Mitsubishi Electric Corp Semiconductor laser
US7567601B1 (en) * 2006-05-15 2009-07-28 Finisar Corporation Semiconductor laser having low stress passivation layer
JP4973258B2 (en) * 2007-03-16 2012-07-11 日亜化学工業株式会社 Semiconductor laser device and manufacturing method thereof
JP2008277492A (en) * 2007-04-27 2008-11-13 Matsushita Electric Ind Co Ltd Semiconductor light-emitting device and method of manufacturing the same
US8073031B2 (en) * 2008-03-03 2011-12-06 Sharp Kabushiki Kaisha Laser diode with improved heat dissipation
JP2010016281A (en) * 2008-07-07 2010-01-21 Mitsubishi Electric Corp Method for manufacturing semiconductor laser
JP2010245378A (en) * 2009-04-08 2010-10-28 Panasonic Corp Nitride semiconductor laser device
DE102009058796A1 (en) * 2009-12-18 2011-06-22 OSRAM Opto Semiconductors GmbH, 93055 Optoelectronic component and method for producing an optoelectronic component
JP5872790B2 (en) * 2011-04-28 2016-03-01 ウシオオプトセミコンダクター株式会社 Semiconductor laser device
CN103392275B (en) * 2011-06-14 2016-08-17 古河电气工业株式会社 Light device, the manufacture method of light device and laser module
DE102014105191B4 (en) * 2014-04-11 2019-09-19 Osram Opto Semiconductors Gmbh Semiconductor strip laser and semiconductor device
JP6388838B2 (en) * 2015-03-09 2018-09-12 Ｎｔｔエレクトロニクス株式会社 Optical functional element
US9865520B2 (en) * 2015-08-07 2018-01-09 International Business Machines Corporation Tunable semiconductor band gap reduction by strained sidewall passivation
WO2018109857A1 (en) * 2016-12-14 2018-06-21 三菱電機株式会社 Method for manufacturing optical semiconductor device
US11616342B2 (en) * 2018-04-02 2023-03-28 Mitsubishi Electric Corporation Semiconductor optical element, semiconductor optical integrated element, and method for manufacturing semiconductor optical element
US11791610B2 (en) * 2018-08-20 2023-10-17 Mitsubishi Electric Corporation Semiconductor laser device manufacturing method and semiconductor laser device

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