JP2006261407A - Semiconductor laser element, and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a semiconductor laser element and the manufacturing method thereof wherein its operating current Iop is made stable. <P>SOLUTION: The semiconductor laser element has: a substrate 11; a first clad layer 12 formed on the principal surface of the substrate 11; an active layer 14 formed above the first clad layer 12; a second clad layer 19 formed above the active layer 14 whose top is so processed as to be a stripe-form ridge waveguide 18; a contact layer 20 formed on the top surface of the ridge waveguide 18; an insulation film 21 formed on the top of the second clad layer wherefrom the top surface of the contact layer 20 is excluded; a hydrogen-impermeability film 22 so formed as to cover the top surface and both the side surfaces of the ridge waveguide 18; hydrogen adding regions 23, 24 formed in the portions of the second clad layer 19 which are present on both the sides of the ridge waveguide 18; and electrodes 25, 26 for bringing the active layer 14 into an electric continuity. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a semiconductor laser device and a manufacturing method thereof, and more particularly to a semiconductor laser device having a stable operating current and a manufacturing method thereof.

  In recent years, semiconductor laser elements having a wavelength of 600 nm to 700 nm using InGaAlP-based materials have been put to practical use in DVDs (Digital Versatile Disks) and the like. High output is progressing.

  Conventionally, as a high-power semiconductor laser element, a semiconductor laser element using a current confinement structure for concentrating current in a current injection region is known (for example, see Patent Document 1).

The semiconductor laser device disclosed in Patent Document 1 has a lower cladding layer, an active layer, and an upper cladding layer that are sequentially formed on a semiconductor substrate.
The upper cladding layer has a laminated structure of an upper first cladding layer, an etching stop layer, and an upper second cladding layer, and the upper second cladding layer is processed into a striped ridge waveguide shape.

  In the upper first cladding layer on both sides of the ridge waveguide, an ion-implanted region in which hydrogen ions are implanted and high resistance is formed by a self-alignment process using a photoresist formed on the upper surface of the ridge waveguide as a mask. Has been.

  The ion implantation region with increased resistance is used as a current confinement layer, and current is concentrated in the current implantation region.

However, in the semiconductor laser element disclosed in Patent Document 1, the threshold current Ith increases due to heat treatment in the manufacturing process of the semiconductor laser element, or the operating current Iop varies due to high-temperature energization in the reliability test process of the semiconductor laser element. There are problems such as.
US Pat. No. 5,696,784 (FIG. 4)

  The present invention provides a semiconductor laser device having a stable operating current Iop and a method for manufacturing the same.

  In order to achieve the above object, in a semiconductor laser device of one embodiment of the present invention, a substrate, a first cladding layer formed on a main surface of the substrate, an active layer formed on the first cladding layer, A second cladding layer formed on the active layer and processed into a striped ridge waveguide shape; a contact layer formed on the upper surface of the ridge waveguide; and an upper surface and both sides of the ridge waveguide At least one of a hydrogen-impermeable film and a hydrogen-absorbing film formed so as to cover the surface, a hydrogen-added region formed in the second cladding layer on both sides of the ridge waveguide, and the active layer And an electrode for obtaining electrical continuity.

  In the method of manufacturing a semiconductor laser device according to one aspect of the present invention, a step of sequentially forming a first cladding layer, an active layer, and a second cladding layer on a main surface of a semiconductor substrate, and an upper portion of the second cladding layer are striped. Processing into a ridge waveguide shape, forming at least one of a hydrogen impermeable film and a hydrogen storage film so as to cover an upper surface and both side surfaces of the ridge waveguide, and the hydrogen impermeable film And a step of adding hydrogen to the second cladding layer on both sides of the ridge waveguide using at least one of the hydrogen storage film as a mask.

  According to the present invention, since at least one of the hydrogen impermeable film and the hydrogen storage film is formed so as to cover the upper surface and both side surfaces of the ridge waveguide, it is possible to suppress diffusion of hydrogen from the gas phase to the current injection region. can do.

As a result, it is possible to prevent the hydrogen dissociated by the temperature rise and released into the gas phase from diffusing into the current injection region to inactivate the dopant.
Therefore, it is possible to provide a semiconductor laser device having a stable operating current Iop.

  Embodiments of the present invention will be described below with reference to the drawings.

  A semiconductor laser device according to Example 1 of the present invention will be described with reference to FIGS. FIG. 1 is a diagram showing a semiconductor laser device, which is a cross-sectional view of the semiconductor laser device cut along a plane perpendicular to the laser light emission direction, and FIGS. 2 and 3 are cross-sectional views sequentially showing the manufacturing steps of the semiconductor laser device.

As shown in FIG. 1, the semiconductor laser device 10 of the present example has an n-In _0.5 (Ga _0.3 Al _0.7 ) _{0. 5} P first cladding layer 12 (hereinafter referred to as n-InGaAlP first cladding layer 12) and, for example, a 20 nm-thick In _0.5 (Ga _0.5 Al _0.5 ) _0.5 P first light guide Layer 13 (hereinafter referred to as InGaAlP first light guide layer 13), for example, an In _0.5 Ga _0.5 P well layer having a thickness of 5 nm and an In _0.5 (Ga _0.5 Al _{0. 5} ) MQW active layer 14 in which _0.5 P barrier layers are alternately stacked three times, and In _0.5 (Ga _0.5 Al _0.5 ) _0.5 P second light guide layer 15 having a thickness of 6 nm, for example. (Hereinafter referred to as InGaAlP first light guide layer 15) are sequentially formed. That.

Further, on the InGaAlP second light guide layer 15, for example, a p-In _0.5 (Ga _0.3 Al _0.7 ) _0.5 P cladding layer 16 (hereinafter referred to as a p-InGaAlP cladding layer) having a thickness of 0.25 μm. 16), a p-In _0.5 Ga _0.5 P (hereinafter referred to as InGaP) etching stop layer 17 having a thickness of 10 nm, and a p-In _0.5 (Ga having a thickness of 1.8 μm, for example. A p-InGaAlP second clad layer 19 in which a _0.3 Al _0.7 ) _0.5 P clad layer 18 (hereinafter referred to as a p-InGaAlP clad layer 18) is laminated is formed.

  The p-InGaAlP cladding layer 18 above the p-InGaAlP second cladding layer 19 is processed into a striped ridge waveguide shape.

  Further, a p-GaAs contact layer 20 having a thickness of 0.2 μm, for example, is formed on the p-InGaAlP cladding layer 18.

  On the portion other than the upper surface of the p-GaAs contact layer 20, an insulating film 21, for example, a silicon oxide film having a thickness of 0.2 μm, is formed as a current blocking layer.

  The upper surface and both side surfaces of the ridge waveguide 18 are covered with a conductive hydrogen impermeable film 22 via a p-GaAs contact layer 20 and an insulating film 21.

  Hydrogen-added regions 23 and 24 to which hydrogen is added are formed in the p-InGaAlP cladding layer 16 on both sides of the ridge waveguide 18.

  A p-side electrode 25 is formed on the upper surface of the p-GaAs contact layer 20, and an n-side electrode 26 is formed on the lower surface of the n-GaAs substrate 11.

In the hydrogenated regions 23 and 24, the added hydrogen is combined with a p-type dopant, for example, zinc (Zn), to inactivate the dopant, so that the resistance is higher than that in the region to which no hydrogen is added.
Since the high-resistance hydrogen-added regions 23 and 24 become current confinement layers, current can be concentrated in the current injection region 27 to which no hydrogen is added.

  As the hydrogen impermeable film 22, for example, a titanium nitride (TiN) film having a thickness of about 0.2 μm, for example, which is conductive and does not transmit hydrogen is suitable.

Next, a method for manufacturing the semiconductor laser element 10 will be specifically described.
As shown in FIG. 2A, an n-GaAs buffer layer (not shown), an n-InGaAlP first cladding layer 12, and the like are formed on an n-GaAs substrate 11 by, for example, MOCVD (Metal Organic Chemical Vapor Deposition). The InGaAlP first optical guide layer 13, the MQW active layer 14, and the InGaAlP second optical guide layer 15 are epitaxially grown over the entire surface in this order.

  Further, the p-InGaAlP second clad layer 19 in which the p-InGaAlP clad layer 16, the p-InGaP etching stop layer 17, and the p-InGaAlP clad layer 18 are laminated, and the p-GaAs contact layer 20 are entirely covered in this order. Epitaxially grow.

  Next, as shown in FIG. 2B, the p-GaAs contact layer 20 to the p-InGaP etching stop layer 17 are removed by selective etching using etching solutions having different compositions by photolithography technology and selective etching technology. Then, the p-InGaAlP cladding layer 18 is processed into a striped ridge waveguide shape.

  Next, as shown in FIG. 3A, after forming a silicon oxide film having a thickness of 0.2 μm as an insulating film 21 on the n-GaAs substrate 11 by, for example, a CVD (Chemical Vapor Deposition) method, The p-GaAs contact layer 20 is exposed by photolithography.

Next, after a TiN film having a thickness of 0.2 μm is formed on the entire surface of the n-GaAs substrate 11 as a hydrogen impermeable film 22 by, for example, reactive sputtering, the upper surface and both side surfaces of the ridge waveguide 18 are formed. In addition, the hydrogen impermeable film 22 is selectively removed by, for example, RIE (Reactive Ion Etching) method.
Thereby, the ridge waveguide 18 whose upper surface and both side surfaces are covered with the hydrogen impermeable film 22 is formed.

  Next, as shown in FIG. 3B, hydrogen plasma is irradiated on the n-GaAs substrate 11 using the hydrogen-impermeable film 22 as a mask, for example, under conditions of a pressure of 5 to 250 mTorr and an applied power of 100 to 5000 W. Then, hydrogen is diffused into the p-InGaAlP cladding layer 16 to form hydrogenated regions 23 and 24. A region sandwiched between the hydrogenation regions 23 and 24 is a current injection region 27.

Next, platinum and gold are sequentially formed on the upper surface of the p-GaAs contact layer 20 as the p-side electrode 25.
Next, after thinning the n-GaAs substrate 11 by polishing, a gold-germanium alloy and gold are sequentially formed as the n-side electrode 26.
Thereafter, the p-side electrode 25 and the n-side electrode 26 are alloyed by performing heat treatment at 400 to 500 ° C. in a mixed gas of hydrogen and nitrogen.

  Finally, the wafer thus fabricated is cleaved in a bar shape parallel to the ridge waveguide 18 and the bars are separated into chips, thereby completing the semiconductor laser device 10 shown in FIG.

  FIG. 4 is a diagram schematically showing the effect of the hydrogen-impermeable film 22. FIG. 4 (a) is a diagram showing a process of forming hydrogenation regions 23 and 24 by irradiating hydrogen plasma, and FIG. 4 (b). FIG. 4 is a diagram showing a process of forming a p-side electrode 25 and an n-side electrode 26 by heat treatment in a mixed gas of hydrogen and nitrogen, and FIG. 4C is a diagram showing a reliability test process by high-temperature energization.

  As shown in FIG. 4A, when hydrogen plasma is irradiated, hydrogen diffuses from the vapor phase into the p-InGaAlP cladding layer 16 not covered with the hydrogen impermeable film 22. The diffused hydrogen combines with the dopant zinc to inactivate the dopant, so that hydrogenated regions 23 and 24 having high resistance values are formed.

  On the other hand, in the ridge waveguide 18 whose upper surface and both side surfaces are covered with the hydrogen impermeable film 22, the hydrogen impermeable film 22 serves as a protective mask, and hydrogen from the gas phase enters the ridge waveguide 18 and the current injection region 27. Can prevent diffusion. As a result, it is possible to suppress inactivation of the dopant by hydrogen.

  Next, as shown in FIG. 4B, when heated by a heater 28 in a mixed gas of hydrogen and nitrogen, in the hydrogenation regions 23 and 24, part of the hydrogen is dissociated from zinc and is in the gas phase. To be released.

  However, since the upper surface and both side surfaces of the ridge waveguide 18 are covered with the hydrogen impermeable film 22, hydrogen released into the gas phase diffuses into the ridge waveguide 18 and the current injection region 27. Doping can be prevented. As a result, it is possible to suppress inactivation of the dopant by hydrogen.

  Next, as shown in FIG. 4C, when the semiconductor laser element 10 is accommodated in the thermostatic chamber 29 and is aged at, for example, 80 ° C., the semiconductor laser element 10 is heated by internal heat generation. Similar to (b), some hydrogen is dissociated from zinc and released into the gas phase.

  However, since the upper surface and both side surfaces of the ridge waveguide 18 are covered with the hydrogen impermeable film 22, hydrogen released into the gas phase diffuses into the ridge waveguide 18 and the current injection region 27. Doping is prevented. As a result, it is possible to suppress inactivation of the dopant by hydrogen.

  As a result, it is possible to suppress an increase in the threshold current Ith due to heat treatment in the manufacturing process of the semiconductor laser element 10 or a variation in the operating current Iop due to high-temperature energization in the reliability test process of the semiconductor laser element 10.

  FIG. 5 is a perspective view in which a part of an envelope showing a configuration of a semiconductor laser device using the semiconductor laser element 10 shown in FIG. 1 is cut away.

  As shown in FIG. 5, the semiconductor laser device 31 of the present embodiment monitors the semiconductor laser element 10 and laser light on a metal stem 33 that is implanted with four lead pins 32 electrically insulated. A monitor photodiode 34 is fixed.

  The semiconductor laser element 10 is mounted on an insulative submount 35 and is fixed perpendicularly to the stem 33 so as to extract laser light on the opposite side of the stem 33. The monitor photodiode 34 is fixed to the stem 33 below the semiconductor laser element 10.

  The semiconductor laser element 10 and the monitor photodiode 34 are electrically connected to the lead pin 32 by a wire or the like.

  A metallic cap 36 encloses the semiconductor laser element 10 and the monitor photodiode 34 and is sealed to the stem 33. A window glass 37 for extracting laser light is provided on the top of the cap 36, and the visible laser light 38 from the semiconductor laser element 10 passes through the window glass 37 from one end face of the semiconductor laser element 10 and serves as an envelope. Laser light emitted from the other end face is incident on a monitor photodiode 34 for controlling light emission.

  As described above, in the semiconductor laser device 10 according to the first embodiment, since the hydrogen impermeable film 22 is formed so as to cover the upper surface and both side surfaces of the ridge waveguide 18, hydrogen in the gas phase is transferred to the ridge waveguide. 18 and the current injection region 27 can be prevented from diffusing.

As a result, it is possible to prevent hydrogen from being combined with zinc in the ridge waveguide 18 and the current injection region 27 and inactivating the dopant.
Therefore, it is possible to provide a semiconductor laser element and a semiconductor laser device with a stable operating current Iop.

  FIG. 6 is a cross-sectional view of a semiconductor laser device according to a second embodiment of the present invention, taken along a plane perpendicular to the laser light emission direction.

  In the present embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, description thereof will be omitted, and different portions will be described.

  This embodiment differs from the first embodiment in that the upper surface and both side surfaces of the ridge waveguide are covered with a hydrogen storage film.

  That is, as shown in FIG. 6, in the semiconductor laser device 50 of this example, the upper surface and both side surfaces of the ridge waveguide 18 are covered with the hydrogen storage film 51.

  As the hydrogen storage film 51, for example, a palladium (Pd) film having conductivity and a property of storing hydrogen is suitable. The palladium (Pd) film can be formed by sputtering, for example.

  FIG. 7 is a diagram schematically showing the effect of the hydrogen storage film 51. FIG. 7A is a diagram showing a process of forming hydrogenation regions 23 and 24 by irradiating hydrogen plasma, and FIG. It is a figure which shows the process of heat-processing in the mixed gas of hydrogen and nitrogen, and forming the p side electrode 25 and the n side electrode 26. FIG.

  As shown in FIG. 7A, in the ridge waveguide 18 whose upper surface and both side surfaces are covered with the hydrogen storage film 51 even when the hydrogen plasma is irradiated, the hydrogen in the vicinity of the surface of the hydrogen storage film 51 is hydrogen. Occluded in the occlusion film 51, hydrogen is prevented from diffusing into the ridge waveguide 18 and the current injection region 27. As a result, it is possible to suppress inactivation of the dopant by hydrogen.

  As shown in FIG. 7B, even if a part of hydrogen bonded to zinc is dissociated and released into the gas phase, the ridge waveguide 18 is covered with the hydrogen storage film 51 on the upper surface and both side surfaces. Therefore, the so-called auto-doping in which hydrogen released into the gas phase diffuses into the ridge waveguide 18 and the current injection region 27 is prevented. As a result, it is possible to suppress inactivation of the dopant by hydrogen. The same applies to the reliability test process by high-temperature energization, and the description thereof is omitted.

  As described above, in the semiconductor laser device 50 according to the second embodiment, the hydrogen storage film 51 is formed so as to cover the upper surface and both side surfaces of the ridge waveguide 18, so that hydrogen is introduced from the gas phase into the ridge waveguide 18 and Diffusion to the current injection region 27 can be prevented.

  As a result, the inactivation of the dopant by hydrogen can be suppressed. Therefore, it is possible to provide a semiconductor laser element and a semiconductor laser device with a stable operating current Iop.

  FIG. 8 is a diagram showing a semiconductor laser device according to Example 3 of the present invention, and is a cross-sectional view of the semiconductor laser device taken along a plane perpendicular to the laser light emission direction.

  In the present embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, description thereof will be omitted, and different portions will be described.

  This embodiment differs from Embodiment 1 in that the upper surface and both side surfaces of the ridge waveguide are covered with a laminated film in which a hydrogen-impermeable film is laminated on a hydrogen-absorbing film.

  That is, as shown in FIG. 8, in the semiconductor laser device 60 of the present embodiment, the upper surface and both side surfaces of the ridge waveguide 18 are covered with a laminated film 63 in which a hydrogen storage film 61 and a hydrogen impermeable film 62 are laminated. ing.

  Thereby, it is possible to more effectively prevent hydrogen in the gas phase from diffusing into the ridge waveguide 18 and the current injection region 27.

  As described above, in the semiconductor laser device 60 according to the third embodiment, the upper surface and both side surfaces of the ridge waveguide 18 are covered with the stacked film 63 in which the hydrogen storage film 61 and the hydrogen impermeable film 62 are stacked. There is an advantage that a higher effect can be obtained in suppressing the diffusion of hydrogen.

  Here, the case where the upper surface and both side surfaces of the ridge waveguide 18 are covered with the laminated film 63 in which the hydrogen-impermeable film 62 is laminated on the hydrogen-occlusion film 61 has been described, but the hydrogen-impermeable film is reversed in the lamination order. 62 may be covered with a laminated film in which the hydrogen storage film 61 is laminated.

  FIG. 9 is a diagram showing a semiconductor laser device according to Example 4 of the present invention, and is a cross-sectional view of the semiconductor laser device taken along a plane perpendicular to the laser light emission direction.

  In the present embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, description thereof will be omitted, and different portions will be described.

  This embodiment differs from the first embodiment in that the upper surface and both side surfaces of the ridge waveguide are covered with a laminated film in which a hydrogen storage film is laminated on a hydrogen storage film, and this laminated film is further covered on both side faces of the ridge waveguide. To the p-InGaAlP cladding layer.

  That is, as shown in FIG. 9, the ridge waveguide 18 of the semiconductor laser device 70 of the present embodiment extends from the both side surfaces of the ridge waveguide 18 onto the p-InGaAlP cladding layer 16 by a distance L1, for example, about 5 to 10 μm. The film is covered with a laminated film 74 in which a hydrogen-impermeable film 73 and a hydrogen-impermeable film 73 are laminated.

  FIG. 10 is a diagram schematically showing the effect of the hydrogen storage film 72 formed by stretching on the p-InGaAlP cladding layer 16, and FIG. 10 (a) shows a p-type heat treatment in a mixed gas of hydrogen and nitrogen. The figure which shows the process of forming the side electrode 25 and the n side electrode 26, FIG.10 (b) is a figure which shows the reliability test process by high temperature electricity supply.

  As shown in FIG. 10A, when the semiconductor laser element 70 is heated by the heater 28 in a mixed gas of hydrogen and nitrogen, a part of hydrogen bonded to zinc is dissociated in the hydrogenation regions 23 and 24. In addition to being released into the gas phase, part of the dissociated hydrogen also diffuses into the p-InGaAlP cladding layers 16 and 18 as indicated by the dashed arrow a.

  The hydrogen diffused in the p-InGaAlP cladding layers 16 and 18 bonds with the dopant zinc and deactivates the dopant soon after being released into the gas phase.

  As a result, the widths of the ridge waveguide 18 and the current injection region 27 are narrowed, which may increase the threshold current Ith and change the operating current Iop.

  However, by providing the extending portion 71, hydrogen is stored in the hydrogen storage film 72 of the extending portion 71, so that diffusion into the p-InGaAlP cladding layers 16 and 18 is suppressed. As a result, it is possible to suppress the inactivation of the dopant.

  As shown in FIG. 10B, when the semiconductor laser element 70 is accommodated in the thermostatic chamber 29 and energized at a high temperature, the semiconductor laser element 70 is heated by internal heat generation. In this case as well, as in FIG. In addition, since the diffused hydrogen is occluded by the hydrogen occlusion film 72 of the extending portion 71, diffusion into the p-InGaAlP cladding layers 16 and 18 is suppressed. As a result, it is possible to suppress the inactivation of the dopant.

  As described above, the semiconductor laser device 70 according to the fourth embodiment has an advantage that hydrogen can be prevented from diffusing in the p-InGaAlP cladding layers 16 and 18.

  Here, the case where the hydrogen impermeable film 73 is also formed on the p-InGaAlP clad layer 16 from both sides of the ridge waveguide 18 has been described. However, the hydrogen impermeable film 73 is formed on the p-InGaAlP clad layer. It does not need to be stretched on 16.

  In the above-described embodiments, the case where the hydrogen addition regions 23 and 24 are formed by hydrogen plasma irradiation has been described. However, the present invention is not limited to this, and heat treatment in a hydrogen atmosphere and a high hydrogen content. The hydrogenation regions 23 and 24 may be formed by coating with a silicon nitride film by plasma CVD and performing heat treatment.

  Further, the p-type dopant in the ridge waveguide 18 and the current injection region 27 may be magnesium (Mg) other than zinc.

  Furthermore, the present invention can be applied not only to InGaAlP-based semiconductor laser elements but also to GaN-based and GaAlAs-based semiconductor laser elements.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows the structure of the semiconductor laser element concerning Example 1 of this invention, and sectional drawing cut | disconnected by the surface parallel to the radiation direction of a laser beam. The process drawing which shows the manufacturing process of the semiconductor laser element which concerns on Example 1 of this invention in order. The process drawing which shows the manufacturing process of the semiconductor laser element which concerns on Example 1 of this invention in order. The figure explaining the effect of the hydrogen-impermeable film which concerns on Example 1 of this invention. 1 is a perspective view in which a part of an envelope showing a configuration of a semiconductor laser device according to a first embodiment of the present invention is cut away. FIG. FIG. 6 is a diagram showing the structure of a semiconductor laser device according to Example 2 of the present invention, and is a cross-sectional view cut along a plane parallel to the laser light emission direction. The figure explaining the effect of the hydrogen storage film which concerns on Example 2 of this invention. It is a figure which shows the structure of the semiconductor laser element which concerns on Example 3 of this invention, and sectional drawing cut | disconnected by the surface parallel to the radiation direction of a laser beam. FIG. 10 is a diagram showing the structure of a semiconductor laser device according to Example 4 of the present invention, and is a cross-sectional view cut along a plane parallel to the laser light emission direction. The figure explaining the effect of the extending | stretching part of the hydrogen storage film which concerns on Example 4 of this invention.

Explanation of symbols

10, 50, 60, 70 Semiconductor laser device 11 n-GaAs substrate 12 n-InGaAlP first cladding layer 13 InGaAlP first light guide layer 14 MQW active layer 15 InGaAlP second light guide layer 16 p-InGaAlP first cladding layer 17 p-InGaP etching stop layer 18 p-InGaAlP cladding layer (ridge waveguide)
19 p-InGaAlP second cladding layer 20 p-GaAs contact layer 21 insulating films 22, 62, 73 hydrogen-impermeable films 23, 24 hydrogen-added region 25 p-side electrode 26 n-side electrode 27 current injection region 28 heater 29 constant temperature bath 31 Semiconductor Laser Device 32 Lead Pin 33 Stem 34 Monitor Photodiode 35 Insulating Submount 36 Cap 37 Window Glass 38 Laser Light 51, 61, 72 Hydrogen Storage Film 71 Extending Parts 63, 74 Laminated Film

Claims (5)

A substrate,
A first cladding layer formed on a main surface of the substrate;
An active layer formed on the first cladding layer;
A second cladding layer formed on the active layer and processed into a striped ridge waveguide shape on the top;
A contact layer formed on the upper surface of the ridge waveguide;
At least one of a hydrogen impermeable film and a hydrogen storage film formed so as to cover the upper surface and both side surfaces of the ridge waveguide;
Hydrogenation regions formed in the second cladding layer on both sides of the ridge waveguide;
An electrode for establishing electrical continuity with the active layer;
A semiconductor laser device comprising:   2. The semiconductor laser device according to claim 1, wherein the hydrogen impermeable film is a titanium nitride (TiN) film.   2. The semiconductor laser device according to claim 1, wherein the hydrogen storage film is a palladium (Pd) film.   4. The semiconductor laser device according to claim 1, wherein the hydrogen storage film is formed by extending from both side surfaces of the ridge waveguide onto the second cladding layer. 5. A step of sequentially forming a first cladding layer, an active layer, and a second cladding layer on a main surface of a semiconductor substrate;
Processing the upper portion of the second cladding layer into a striped ridge waveguide shape;
Forming at least one of a hydrogen impermeable film and a hydrogen storage film so as to cover the upper surface and both side surfaces of the ridge waveguide;
Adding hydrogen to the second cladding layer on both sides of the ridge waveguide, using at least one of the hydrogen impermeable film and the hydrogen storage film as a mask;
A method for manufacturing a semiconductor laser device, comprising:

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