JP2013251428A - Semiconductor laser element, semiconductor laser device equipped with the same and semiconductor laser element manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a semiconductor laser element which can inhibit variation in current flowing through a photodiode at the time of a long-term conduction test at a constant current, and which can provide luminescence with a stable optical output.SOLUTION: A semiconductor laser element 10 comprises: a nitride semiconductor laminate 20 in which a plurality of semiconductor layers are laminated on a substrate 11; a resonator end face 16 formed at an end of the nitride semiconductor laminate 20; and an AR protection film laminate 17 and an HR protection film laminate 18 which cover the resonator end face 16. In each of the AR protection film laminate 17 and the HR protection film laminate 18, a protection film of one intermediate layer is formed by using materials contained by neighboring two other layers in at least one set of successive three layers of protection films, or each protection film of at least a pair of two successive layers is formed to contain a first material and a second material, and one of the protection films contains the first material at a rate greater than the second material, and the other protection film contains the second material at a rate greater than the first material.

Description

  The present invention relates to a semiconductor laser element, a semiconductor laser device including the same, and a method for manufacturing the semiconductor laser element.

  In recent years, various semiconductor laser elements have been widely used as light sources for optical disk devices. For example, as a light source for CD (Compact Disc) and DVD (Digital Versatile Disc), an aluminum gallium arsenide (AlGaAs) or aluminum gallium indium phosphide (AlGaInP) semiconductor laser element is mainly used. For example, a blue-violet semiconductor laser element using a group III-V nitride semiconductor such as gallium nitride (GaN) is mainly used for BD (Blu-ray Disc (trademark)).

  It is known that when these semiconductor laser elements emit light with high light output, COD (Catastrophic Optical Damage) is likely to occur, and the reliability of the semiconductor laser element decreases. Therefore, it is indispensable to improve the COD level in order to achieve both high output of the semiconductor laser element and improvement of stability, reliability and durability.

  Therefore, a technique for improving the COD level in the semiconductor laser element has been proposed, and the conventional technique is disclosed in Patent Document 1. The conventional semiconductor laser element described in Patent Document 1 includes a plurality of protective films having a crystal structure on its end face, that is, on the cavity end face.

JP 2008-182208 A

  When a semiconductor laser element is used as a light source for an optical disk device, it is necessary to cause the semiconductor laser element to emit light with a constant light output. In order to keep the light output of the semiconductor laser element constant, generally, light output control is executed by monitoring light emitted from a resonator end face having a high reflectance using a photodiode.

  On the other hand, as the output of the semiconductor laser device is increased and the size of the chip is reduced, the current value flowing through the photodiode greatly fluctuates during a long-term energization test with a constant current, resulting in a problem that the light output is not stable.

  The present invention has been made in view of the above points, and can suppress fluctuations in the current flowing through a photodiode during a long-term energization test at a constant current and can emit light with a stable light output. An object is to provide an element, a semiconductor laser device including the element, and a method for manufacturing the semiconductor laser element.

  In order to solve the above problems, a semiconductor laser device according to the present invention includes a semiconductor laminated portion formed by laminating a plurality of semiconductor layers, and parallel to the lamination direction of the semiconductor layers formed at end portions of the semiconductor laminated portion. And a protective film laminated portion formed by laminating three or more protective films covering the end surface, and the protective film laminated portion comprises at least one set of three consecutive protective films. Among these, the protective film of the intermediate layer is formed using a material contained in each of the two other protective films adjacent to each other.

  According to another aspect of the present invention, there is provided a semiconductor laser device comprising: a semiconductor laminated portion formed by laminating a plurality of semiconductor layers; an end face parallel to a lamination direction of the semiconductor layer formed at an end of the semiconductor laminated portion; and the end face A protective film laminate formed by laminating three or more protective films covering the protective film, wherein the protective film laminate includes at least one set of two consecutive protective films each including the first material and the second protective film. It is formed containing a material and one of the protective films has a higher content ratio of the first material than the second material, and the other protective film has a higher content ratio of the second material than the first material. It is a feature.

  According to these configurations, the intermediate protective film of the set of three consecutive protective films suppresses fluctuations in light reflectance caused by diffusion of the other two protective film materials. Further, each of the set of two successive protective films formed by containing the first material and the second material suppresses fluctuations in the reflectance of light caused by the diffusion of the other protective film material. Therefore, fluctuations in the current flowing through the photodiode during a long-term energization test with a constant current are suppressed.

  Further, in the semiconductor laser device having the above configuration, the protective film may be an oxide of Si, Mg, Al, Hf, Nb, Zr, Sc, Ta, Ga, Zn, Y, B, Ti, or a nitride thereof or an oxide thereof. It is characterized by being made of fluoride. According to this configuration, fluctuations in light reflectance are suppressed.

  Further, in the semiconductor laser device having the above-described configuration, the gas component is the same among the materials contained in each of the protective films used for forming the protective film laminated portion. According to this configuration, in addition to suppressing fluctuations in the reflectance of light, the process of forming the protective film is facilitated.

  In the semiconductor laser device having the above-described configuration, the set of continuous protective films is arranged closest to the end face in the protective film laminated portion. Since the protective film adjacent to the end face in the protective film laminated portion is most susceptible to light and heat, this configuration improves the effect of suppressing fluctuations in light reflectance.

  Further, in the semiconductor laser device having the above-described configuration, the end surface mainly includes an emission side end surface that is a side from which laser light is emitted, and a reflection side end surface that is the opposite side, and the protective film stack is disposed on the emission side end surface. And formed on each of the reflection side end faces, the light reflectance of the protective film lamination portion on the emission side end face and the protection film lamination portion on the reflection side end face are different from each other.

  In the present invention, a semiconductor laser device includes the semiconductor laser element. According to this configuration, fluctuations in the current flowing through the photodiode during a long-term energization test with a constant current in the semiconductor laser device are suppressed.

  In order to solve the above problems, a method of manufacturing a semiconductor laser device according to the present invention includes a step of stacking a plurality of semiconductor layers to form a semiconductor stacked portion, a stacking direction of the semiconductor layers in the semiconductor stacked portion, and Forming a parallel end face; and forming a protective film laminate portion covering the end face by laminating three or more protective films, wherein the protective film laminate portion is at least one set of continuous layers. Among the three protective films, the intermediate protective film is formed using a material contained in each of the two adjacent protective films adjacent to each other.

  The method of manufacturing a semiconductor laser device of the present invention includes a step of stacking a plurality of semiconductor layers to form a semiconductor stacked portion, and a step of forming an end surface parallel to the stacking direction of the semiconductor layers in the semiconductor stacked portion. Laminating three or more protective films to form a protective film laminated portion that covers the end face, and the protective film laminated portion includes at least one set of two successive protective films each of which is a first layer. It is formed containing one material and a second material, and one of the protective films contains a higher proportion of the first material than the second material, and the other protective film contains the second material more than the first material. It is characterized by a high percentage.

  According to the configuration of the present invention, it is possible to suppress fluctuations in the reflectance of light caused by the diffusion of the protective film material on the end face of the semiconductor laser element. Therefore, a semiconductor laser element capable of suppressing fluctuations in the current flowing through the photodiode during a long-term energization test at a constant current and capable of emitting light with a stable light output, and a semiconductor laser device and a semiconductor laser element including the semiconductor laser element The manufacturing method of can be provided.

1 is a side view of a semiconductor laser device according to an embodiment of the present invention. 1 is a plan view of a semiconductor laser device according to an embodiment of the present invention. It is sectional drawing in the III-III line of the semiconductor laser element shown in FIG. It is a front view of the semiconductor wafer which has the semiconductor laser element which concerns on embodiment of this invention. It is a top view of a semiconductor wafer which has a semiconductor laser device concerning an embodiment of the present invention. 1 is a side view of a semiconductor wafer having a semiconductor laser device according to an embodiment of the present invention. It is an external appearance perspective view of the semiconductor laser apparatus provided with the semiconductor laser element concerning the embodiment of the present invention, and shows the state where a cap was removed. 1 is an external perspective view of a semiconductor laser device including a semiconductor laser element according to an embodiment of the present invention.

  Prior to practicing the present invention, analysis was performed on samples in which fluctuations in the monitor current of the photodiode occurred. When the semiconductor laser device was driven for a long period of time, the monitor current fluctuated greatly at the beginning of driving, and the fluctuation of the monitor current became small as the driving time passed. Further, as a result of analyzing the element in which the fluctuation occurred in order to elucidate the cause of the fluctuation of the monitor current, it was found that the material of the protective film was diffused to other protective films and semiconductor layers. This diffusion phenomenon is caused by the influence of heat and light generated during laser oscillation. In particular, the problem of diffusion of the protective film due to heat generation has increased due to the progress of higher output of the semiconductor laser device and reduction of the chip. It is considered that due to this diffusion, the reflectance of the entire protective film changes during the long-term energization test, and the amount of light incident on the photodiode also fluctuates. From this, it can be considered that when the laser is driven for a long period of time, the variation in reflectance is large at the initial stage where the protective film material diffuses, causing the variation in light output. Based on the above analysis, a simple and highly effective method for suppressing the fluctuation of reflectance at the initial stage of laser driving is proposed.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS.

  First, the outline of the structure of the semiconductor laser device according to the embodiment of the present invention will be described with reference to FIGS. 1 is a side view of the semiconductor laser device, FIG. 2 is a plan view of the semiconductor laser device, and FIG. 3 is a cross-sectional view of the semiconductor laser device shown in FIG.

  As shown in FIGS. 1 and 3, the semiconductor laser device 10 includes a nitride semiconductor stacked portion 20 in which a plurality of nitride semiconductor layers are stacked on a growth main surface of a substrate 11 made of GaN having a thickness of 100 μm.

As shown in FIG. 3, the nitride semiconductor multilayer unit 20 includes an n-type GaN layer 21 having a thickness of 0.2 μm, an n-type Al _0.05 Ga _0.95 N clad layer 22 having a thickness of 2.5 μm, An n-type GaN guide layer 23 having a thickness of 0.1 μm, a multi-quantum well active layer 24 in which three layers of InGaN well layers having a thickness of 4 nm and four layers of GaN barrier layers having a thickness of 8 nm are alternately stacked, each having a thickness of 20 nm p-type Al _0.3 Ga _0.7 N evaporation preventing layer 25, p-type GaN guide layer 26 having a thickness of 0.08 μm, p-type Al _0.062 Ga _0.938 N cladding layer 27 having a thickness of 0.5 μm, p-type having a thickness of 0.1 μm A GaN contact layer 28 is laminated. The multiple quantum well active layer 24 is formed in the order of barrier layer / well layer / barrier layer / well layer / barrier layer / well layer / barrier layer from the substrate 11 side. Further, the ridge portion 12 of the optical waveguide is formed by vapor phase etching on the p-type Al _0.062 Ga _0.938 N clad layer 27 and the p-type GaN contact layer 28, and further patterned by the insulating film 13 for current confinement. .

  A p-electrode 14 is provided on the nitride semiconductor multilayer portion 20 including the ridge portion 12. On the other hand, an n-electrode 15 is provided on the surface of the substrate 11 opposite to the surface on which the nitride semiconductor multilayer portion 20 is formed (hereinafter sometimes referred to as the back surface).

  The semiconductor laser device 10 includes resonator end faces 16 that are parallel to the stacking direction of the semiconductor layers at both left and right ends of the nitride semiconductor stack 20 in FIGS. 1 and 2. The cavity end face 16 is formed when the semiconductor laser element 10 is formed by cleaving and dividing a semiconductor wafer 30 (see FIGS. 4 to 6) described later. The resonator end face 16 includes an emission side end face 16F that is a side from which the laser light is mainly emitted from the active layer of the nitride semiconductor multilayer portion 20, and a reflection side end face 16R that is opposite to the emission side end face 16F. The nitride semiconductor stacked unit 20 operates as a resonator by the emission side end face 16F and the reflection side end face 16R.

The emission-side end face 16F is covered with an AR (Anti-Reflection) protective film laminate portion 17. The AR protective film stacking portion 17 is formed by stacking three protective films of Al ₂ O ₃ / Al _x1 Ti _x2 O / TiO ₂ . Note that a relationship of 0 <x1 and 0 <x2 is established. For example, x1 = 0.67 and x2 = 0.5. In this way, the AR protective film stacking portion 17 is composed of two protective films (Al ₂ O ₃ , TiO ₂ ) adjacent to the intermediate protective film (Al _x1 Ti _x2 O) among the three consecutive protective films. ₂ ) It is formed using the materials that each contains.

The reflection side end face 16 </ b> R is covered with an HR (High-Reflection) protective film laminated portion 18. The HR protective film laminated portion 18 is made of Al ₂ O ₃ / Si _y1 Ti _y2 O / Si _z1 Ti _z2 O / Si _y1 Ti _y2 O / Si _{z1 Tiz2} O / Si _y1 Ti _y2 O / Si _{z1 Tiz2} O / Si _y1. Ten protective layers of Ti _y2 O / Si _z1 Ti _z2 O / Si _y1 Ti _y2 O are laminated. Note that 0 <y2 <y1 and 0 <z1 <z2 are established. For example, y1 = 0.4, y2 = 0.1, z1 = 0.1, and z2 = 0.4. In this way, the HR protective film laminate 18 includes two successive protective films (Si _y1 Ti _y2 O, Si _z1 Ti _z2 O) each containing the first material (Si) and the second material (Ti). One protective film is higher in content of the first material (Si) than the second material (Ti), and the other protective film is more in the second material (Ti) than in the first material (Si). The content ratio is high.

  Next, a method for manufacturing the semiconductor laser device 10 having the above configuration will be described with reference to FIGS. 4 to 6 in addition to FIGS. 4, 5, and 6 are a front view, a plan view, and a side view of a semiconductor wafer having the semiconductor laser element 10.

  First, the nitride semiconductor multilayer portion 20 is formed from the n-type GaN layer 21 to the p-type GaN contact layer 28 on the substrate 11 made of GaN. The nitride semiconductor stacked portion 20 on the substrate 11 is grown using an epitaxial growth method such as MOCVD (Metal Organic Chemical Vapor Deposition).

Subsequently, the ridge portion 12 is formed on the p-type GaN contact layer 28 and the p-type Al _0.062 Ga _0.938 N cladding layer 27. The ridge portion 12 is formed by vapor phase etching such as RIE (Reactive Ion Etching) and ICP (Inductive Coupled Plasma). Then, the insulating film 13 for current confinement is formed on the upper surface of the nitride semiconductor multilayer portion 20 other than the upper surface of the p-type GaN contact layer 28. The insulating film 13 may be made of, for example, SiO ₂ or ZrO ₂ .

  Subsequently, the p-electrode 14 is formed, and the substrate 11 is ground and polished from the back surface until the thickness of the substrate 11 becomes about 100 μm. The damaged layer formed on the back surface of the substrate 11 in this polishing process is removed by etching by vapor phase etching such as RIE. Thereafter, the n-electrode 15 laminated in the order of Ti / Al from the back surface side of the substrate 11 is formed by EB (Electron Beam) evaporation, and the semiconductor wafer 30 shown in FIGS. 4 to 6 is completed.

  Subsequently, the semiconductor wafer 30 is cleaved into a bar shape and divided to form a semiconductor laser bar having the resonator end face 16. The semiconductor wafer 30 is divided into a plurality of parts along the longitudinal direction of the ridge portion 12 at a scribe point 31 shown in FIGS. That is, the resonator end surface 16 is formed as a plane extending along a direction perpendicular to the longitudinal direction of the ridge portion 12.

  The resonator end face 16 formed by dividing the semiconductor wafer 30 into bars is exposed to the atmosphere, and contaminants such as moisture, natural oxide film, and carbon adhere to it. Therefore, in order to minimize the adhesion of these contaminants to the resonator end face 16 before forming the protective film, it is necessary to keep the vacuum state within a few hours after the cleavage.

Subsequently, the AR protective film laminated portion 17 is formed on the emission side end face 16F of the semiconductor laser bar by an EB vapor deposition apparatus. In the present embodiment, the AR protective film laminated portion 17 is made of a dielectric film and has a three-layer structure of Al ₂ O ₃ / Al _x1 Ti _X2 O / TiO ₂ in order from the emission side end face 16F side.

AR protective film laminated unit 17 first after the formation of the Al ₂ O ₃ using an Al ₂ O ₃ target, using Al ₂ O ₃ / Ti ₃ O ₅ mixed target to form a Al _x1 Ti _X2 O, the TiO ₂ with a thickness of 17 nm is formed on the surface using a Ti ₃ O ₅ target in an oxygen atmosphere. The thickness of the AR protective film laminated portion 17 in the light emission direction is a design value such that the reflectance at the emission side end face 16F of light having a wavelength of 405 nm is 5%.

Further, the HR protective film laminated portion 18 is formed on the reflection side end face 16R of the semiconductor laser bar. The HR protective film laminated portion 18 is made of a dielectric film, and is formed of Al ₂ O ₃ / Si _y1 Ti _y2 O / Si _z1 Ti _z2 O / Si _y1 Ti _y2 O / Si _z1 Ti _z2 O / Si in this order from the reflection side end face 16R. _Y1 Ti _y2 O / Si _z1 Ti _z2 O / Si _y1 Ti _y2 O / Si _z1 Ti _z2 O / Si _y1 Ti _y2 O In the HR protective film laminated portion 18, a multilayer protective film of Si _y1 Ti _y2 O / Si _{z1 Tiz2} plays a role as a basic reflective film. The Al ₂ O ₃ film serves as a protective film for the entire multilayer protective film of Si _y1 Ti _y2 O / Si _{z1 Tiz2} .

SiO ₂ contained in the protective film forming the HR protective film laminate 18 is replaced with Ga of GaN on the reflection side end face 16R and reacts very well at the interface to cause end face deterioration. In addition, when TiO ₂ comes into direct contact with GaN, light may be absorbed by reaction or the like to generate heat, which may cause deterioration of the film itself. Therefore, Al ₂ O ₃ which is stable against GaN is formed on the reflection side end face 16R as a protective film.

In the present embodiment, the thickness of Al ₂ O _{3 in} the HR protective film laminate 18 is about 60 mm. The thickness of Al ₂ O ₃ is preferably 10 mm or more and 200 mm or less, and more preferably 10 mm or more and 100 mm or less. The reason is that when the thickness is less than 10 mm, it is difficult to form a uniform film and the effect as a protective film is small. Further, when the thickness is larger than 100 mm, particularly when the thickness is larger than 200 mm, the reflectance is lowered. Note that Al ₂ O ₃ as a protective film is not necessarily provided.

  The light reflectance at the reflection-side end face 16R covered with the HR protective film laminate 18 is, for example, 90% or more. That is, light is not emitted at all from the reflection-side end face 16R side of the semiconductor laser element 10, and a slight amount of light is emitted. The light emitted from the reflection side end face 16R side is detected by a photodiode 60 which will be described later, and is used for controlling the light output.

  Subsequently, the semiconductor laser bar on which the AR protective film stacked portion 17 and the HR protective film stacked portion 18 are formed is divided into a plurality of chips along a direction perpendicular to the longitudinal direction of the ridge portion 12. Thereby, the semiconductor laser device 10 is completed.

  Next, a method for manufacturing a semiconductor laser device including the semiconductor laser element 10 having the above configuration will be described with reference to FIGS. FIG. 7 is an external perspective view of a semiconductor laser device provided with the semiconductor laser element 10, showing a state in which the cap is removed, and FIG. 8 is an external perspective view of the semiconductor laser device provided with the semiconductor laser element.

  The semiconductor laser element 10 is mounted on the submount 52 of the semiconductor laser device 50 using solder 53 as shown in FIG. As the solder 53, AuSn, SnAgSu, or the like can be used.

  Subsequently, the submount 52 on which the semiconductor laser element 10 is mounted is mounted on the stem 51 via the mount 56 using solder (not shown) such as AuSn. Further, the photodiode 60 is mounted on the surface of the stem 51 on which the light emitted from the reflection-side end face 16R side of the semiconductor laser element 10 hits using solder (not shown) such as AuSn.

  Subsequently, using the wiring 55 made of Au wire, the p-electrode 14 of the semiconductor laser element 10 and the pin 54 of the stem 51 are connected, the submount 52 and the mount 56 are connected, and the photodiode 60 and the pin 62 are connected. Connect. Then, as shown in FIG. 8, the portion where the semiconductor laser element 10 is mounted is sealed together with dry air by a cap 58 provided with a glass window 59. Thereby, the semiconductor laser device 50 is completed.

  The semiconductor laser device 50 is attached to, for example, a wiring board via three lead pins 57 and receives power supply. The laser light emitted from the semiconductor laser element 10 passes through the glass window 59 and is emitted to the outside.

As described above, the semiconductor laser device 10 of the present invention includes the nitride semiconductor stacked unit 20 formed by stacking a plurality of semiconductor layers, and the stacking direction of the semiconductor layers formed at the ends of the nitride semiconductor stacked unit 20. A parallel resonator end face 16, and an AR protective film laminated part 17 and an HR protective film laminated part 18 formed by laminating three or more protective films covering the resonator end face 16 are provided. The AR protective film stack 17 includes each of the other two protective films (Al ₂ O ₃ , TiO ₂ ) adjacent to the intermediate protective film (Al _x1 Ti _X2 O) among the three consecutive protective films. It is formed using the material to do. The HR protective film laminated portion 18 is formed by including two successive protective films (Si _y1 Ti _y2 O, Si _z1 Ti _z2 O) each containing a first material (Si) and a second material (Ti). One protective film has a higher content ratio of the first material (Si) than the second material (Ti), and the other protective film has a higher content ratio of the second material (Ti) than the first material (Si). ing.

As a result, the AR protective film stacking portion 17 has a reflectance of light caused by diffusion of other two protective film materials Al ₂ O ₃ / TiO ₂ adjacent to the intermediate protective film (Al _x1 Ti _X2 O). Variations can be suppressed. In addition, the HR protective film stacking portion 18 is a set of two continuous protective films (Si _y1 Ti _y2 O, Si _z1 Ti _z2 ) formed by containing the first material (Si) and the second material (Ti). O) It is possible to suppress fluctuations in light reflectivity caused by diffusion of other protective film materials. Therefore, it is possible to suppress fluctuations in the current flowing through the photodiode 60 during a long-term energization test with a constant current.

The AR protective film stack 17 and the HR protective film stack 18 can be formed by a known method such as an EB vapor deposition apparatus or a sputter vapor deposition apparatus. Si, Mg, Al, Hf, Nb, Zr, Sc, Ta, Ga , Zn, Y, B, Ti oxides or nitrides thereof (for example, AlN, AlGaN, BN, etc.) or combinations of protective films made of fluorides thereof. For example, in the case of a combination of two protective layers of AlN / SiN, a protective film laminated portion having three consecutive protective films of AlN / Al _x1 Si _x2 N / SiN (0 < _x1, 0 <x2) is formed. In addition, the effect of the present invention can be obtained by forming a protective film laminated portion having two continuous protective films of Al _y1 Si _y2 N / Al _z1 Si _z2 N (0 <y2 <y1, 0 <z1 <z2). It is possible.

  In addition, it is desirable that the gas components of the materials contained in each of the protective films used for forming the AR protective film laminated portion 17 and the HR protective film laminated portion 18 are the same. According to this configuration, in addition to suppressing fluctuations in the reflectance of light, the process of forming the protective film is facilitated.

  And when the protective film lamination | stacking part which covers the resonator end surface 16 is formed with a multilayer protective film of three or more layers, the above-mentioned set of three continuous films which the AR protective film lamination | stacking part 17 has with respect to all the protective films. The structure of the protective film of a layer may be used, and the structure of the above-mentioned set of two continuous protective films which the HR protective film lamination | stacking part 18 has may be used. Moreover, you may use them only for one part. When it is used for all the protective films, the effect of suppressing the variation in reflectance is increased. When it is used only for a part, the effect of suppressing the change in reflectance is reduced, but the manufacturing process becomes easy.

  In addition, when the structure of the present invention is used only for a part of the protective film laminated portion formed of a multilayer protective film of three or more layers, the above-mentioned set of three protective films is formed of the protective film laminated It is desirable that the portion be disposed closest to the resonator end face 16 in the portion. Since the protective film adjacent to the resonator end surface 16 in the protective film laminated portion is most susceptible to light and heat, this configuration can improve the effect of suppressing fluctuations in light reflectance.

  As described above, according to the configuration of the above-described embodiment of the present invention, it is possible to suppress the variation in the reflectance of light caused by the diffusion of the protective film material on the resonator end face 16 of the semiconductor laser element 10. Therefore, the semiconductor laser element 10 capable of suppressing fluctuations in the current flowing through the photodiode 60 during a long-term energization test at a constant current and capable of emitting light with a stable light output, and a semiconductor laser device 50 including the semiconductor laser element 10, A method of manufacturing a semiconductor laser element can be provided.

  Further, since it is not necessary to check the output fluctuation by the acceleration test in the manufacturing process of the semiconductor laser device, the manufacturing process can be simplified.

  Although the embodiments and examples of the present invention have been described above, the scope of the present invention is not limited to these embodiments, and various modifications can be made without departing from the spirit of the invention.

  For example, the scope of application of the present invention is not limited to a semiconductor laser device in which nitride semiconductor layers are stacked, but can also be applied to other semiconductor laser devices having different materials and wavelengths. Can be obtained.

  Further, with respect to the protective film stacking portion covering the resonator end face 16, either one of the configuration of the set of three consecutive protective films and the configuration of the set of two continuous protective films of the present invention. May be used alone, or a combination of these may be used.

  In addition, the configuration of the set of three consecutive protective films or the configuration of the set of two continuous protective films according to the present invention may be used only for the AR protective film stacking portion 17 or the HR protection. You may use only for the film | membrane laminated part 18, and may use it for both. Since it is considered that the HR protective film laminated portion 18 has a high reflectance and a large variation in reflectance due to long-term driving, it is desirable to use the present invention at least for the HR protective film laminated portion 18.

  The present invention can be used in a semiconductor laser device, a semiconductor laser device including the semiconductor laser device, and a method for manufacturing the semiconductor laser device.

10 Semiconductor laser device 11 Substrate 16 Resonator end face (end face)
16F Output side end face (end face)
16R Reflective end face (end face)
17 AR protective film lamination part (protective film lamination part)
18 HR protective film laminate (protective film laminate)
20 Nitride semiconductor stack (semiconductor stack)
30 Semiconductor Wafer 50 Semiconductor Laser Device 60 Photodiode

Claims (9)

A semiconductor laminated portion formed by laminating a plurality of semiconductor layers;
An end face parallel to the stacking direction of the semiconductor layer formed at the end of the semiconductor stack,
A protective film laminated portion formed by laminating three or more protective films covering the end surface;
With
The protective film lamination portion is formed using a material contained in each of the other two protective films adjacent to the intermediate protective film among at least one set of three consecutive protective films. A semiconductor laser device characterized by the above. A semiconductor laminated portion formed by laminating a plurality of semiconductor layers;
An end face parallel to the stacking direction of the semiconductor layer formed at the end of the semiconductor stack,
A protective film laminated portion formed by laminating three or more protective films covering the end surface;
With
The protective film laminated portion includes at least one set of two continuous protective films each containing a first material and a second material, and one of the protective films is made of a first material than a second material. A semiconductor laser device characterized in that the content ratio is higher, and the other protective film has a higher content ratio in the second material than in the first material.   The protective film is made of an oxide of Si, Mg, Al, Hf, Nb, Zr, Sc, Ta, Ga, Zn, Y, B, Ti, a nitride thereof, or a fluoride thereof. The semiconductor laser device according to claim 1 or 2.   3. The semiconductor laser device according to claim 1, wherein a gas component is the same among materials contained in each of the protective films used for forming the protective film laminated portion. 4.   3. The semiconductor laser device according to claim 1, wherein the set of continuous protective films are arranged closest to the end face in the protective film stacking portion. The end face includes an emission side end face which is a side from which laser light is mainly emitted and a reflection side end face which is the opposite side.
The protective film laminated portion is formed on each of the emission side end surface and the reflection side end surface, and the light reflectance of the protective film laminated portion on the emission side end surface and the protective film laminated portion on the reflection side end surface is mutually different. The semiconductor laser device according to claim 1, wherein the semiconductor laser devices are different.   A semiconductor laser device comprising the semiconductor laser element according to claim 1. A step of stacking a plurality of semiconductor layers to form a semiconductor stacked portion;
Forming an end surface parallel to the stacking direction of the semiconductor layers in the semiconductor stacking portion;
A step of forming a protective film laminated portion covering the end face by laminating three or more protective films; and
Including
The protective film lamination portion is formed using a material contained in each of the other two protective films adjacent to the intermediate protective film among at least one set of three consecutive protective films. A method for manufacturing a semiconductor laser device, comprising: A step of stacking a plurality of semiconductor layers to form a semiconductor stacked portion;
Forming an end surface parallel to the stacking direction of the semiconductor layers in the semiconductor stacking portion;
A step of forming a protective film laminated portion covering the end face by laminating three or more protective films; and
Including
The protective film laminated portion includes at least one set of two continuous protective films each containing a first material and a second material, and one of the protective films is made of a first material than a second material. A method for manufacturing a semiconductor laser device, characterized in that the content ratio is higher, and the other protective film has a higher content ratio in the second material than in the first material.

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