JP2007324193A - Nitride semiconductor laser element and nitride semiconductor laser device using same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a highly reliable and high rigidity nitride semiconductor laser element wherein diffusion of water included in the atmosphere is prevented into an end surface of a resonator and into a coating film formed thereon. <P>SOLUTION: Humidity absorption preventing layers 41, 42 of the double-layer structure of SiN/TiN are formed on the coating films 18, 19 formed on the resonator end surfaces 16, 17 of the nitride semiconductor laser element 10. Accordingly, it is possible to prevent that water content in the atmosphere is diffused into a GaN substrate 11 and a nitride semiconductor laminate 20 through the resonator end surfaces 16, 17, and water content is diffused as evaporated from the front surface of the stem, cap, and nitride semiconductor laser element 10 themselves of the nitride semiconductor laser device. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an edge-emitting semiconductor laser device, and more specifically, it suppresses deterioration of the resonator end face due to moisture diffusion to the coat film of the resonator end face and the resonator end face, and is stable for a long time with high output. And a nitride semiconductor laser device including the same.

  In recent years, optical disk systems using nitride semiconductor laser elements, which are blue semiconductor laser elements, have entered the practical stage for the purpose of large-capacity recording. These new discs are capable of higher density and higher speed writing due to the dual-layer discs, so that the COD level is high, and the durability, reliability and high output that operate stably over a long period of time are high. There is a need for nitride semiconductor laser devices. Here, the COD level is a critical output at which COD (Catatrophic Optical Damage) occurs.

In a conventional AlGaAs-based or InGaAlP-based semiconductor laser element for recording and reproducing CDs or DVDs, a dielectric such as SiO _{2 is used} to prevent deterioration and optical damage of the resonator end surface, which is a laser light emission surface and a reflection surface. A coat film made of a film is formed. However, when the dielectric film was formed as it was on the nitride semiconductor laser element using an EB vapor deposition device or a sputtering device, the COD level was low and the output was low. Therefore, improvement of the coating on the resonator end face is required.

  In Patent Document 1, a semiconductor laser is heated and the cavity end face of the semiconductor laser formed by cleavage is exposed to an Ar plasma atmosphere to remove minute irregularities, oxides, contaminants, etc. present on the cavity end face. A semiconductor laser that suppresses deterioration of the resonator end face by flattening the end face of the resonator and forming an end face coat film made of a dielectric to improve the adhesion of the end face coat film to the end face of the resonator. Manufacturing methods have been proposed.

Further, in Patent Document 2, in order to protect the semiconductor laser structure end face of the optical semiconductor element from oxygen and moisture in the environmental atmosphere, in Patent Document 2, the semiconductor laser structure end face is formed with SiN in order from the semiconductor laser structure end face side. An optical semiconductor element in which a thin film comprising two layers of _x / SiO ₂ has been proposed.
Japanese Patent Laid-Open No. 2002-335053 (pages 5-7, FIG. 1) JP-A-7-326823 (pages 5-7, FIG. 1)

  A normal nitride semiconductor laser device is mounted with solder on a submount that acts as a heat sink, that is, a heat sink, and the submount is mounted on a stem that is a support for the semiconductor laser. Thereafter, the nitride semiconductor laser element is electrically connected to the pin of the stem by a gold wire, and sealed with air, dry air, or a rare gas by a cap with a glass window that transmits 90% or more of the laser light.

  As a result of the inventor's repeated research, contaminants such as moisture, carbon, and natural oxide film on the resonator end face are obtained by heating the nitride semiconductor laser element and performing pretreatment by exposing the end face of the resonator to the plasma atmosphere. However, after sealing the package that seals the nitride semiconductor laser element with a cap, moisture diffuses in the dielectric film formed on the resonator end face as time passes, and this moisture covers the end face of the resonator. It turned out to be a factor to deteriorate.

  A conventional nitride semiconductor laser device that has been pretreated by exposure to the plasma atmosphere of the cavity end face is fabricated, and immediately after the fabrication, the moisture concentration in the dielectric film is obtained by sputtering AES (Auger Electron Spectroscopy). Was measured in the depth direction (direction from the atmosphere side toward the resonator end face), and the moisture concentration was below the detection limit over the entire dielectric film. However, when the same nitride semiconductor laser element was allowed to stand for about 300 hours and the moisture concentration was measured in the same manner, the moisture was detected with a concentration profile that decreased from the surface of the dielectric film toward the end face of the semiconductor resonator. This result shows that although moisture adhering to the resonator end face has been removed by the pretreatment, moisture has diffused from the outside into the dielectric film over time. When the COD levels of the nitride semiconductor laser element immediately after fabrication and the nitride semiconductor laser element after standing for 300 hours were measured, it was confirmed that those after standing for 300 hours were lower than those immediately after fabrication. . This suggests that the moisture in the dielectric film is a factor in reducing the COD level.

  If the COD level decreases with time, high output and high durability cannot be realized. FIG. 9 is a graph showing the results of aging the nitride semiconductor laser element just after fabrication, periodically taking it out, and measuring the COD level. In FIG. 9, the horizontal axis represents the aging time, and the vertical axis represents the COD level. The aging conditions are an atmospheric temperature of 70 ° C., an output of 60 mW, CW (continuous wave) driving, and the COD level measurement conditions are 50 ns, duty 50%, room temperature, and pulse measurement. From this result, it can be seen that the COD level after elapse of 300 hours is 200 mW, and that output of 200 mW or more is impossible after 300 hours have elapsed.

  Moisture diffusing into the dielectric film formed on the laser light emitting end face of the resonator end face of the semiconductor laser element is basically present in the atmosphere, and is also present on the surface of the stem, cap, and semiconductor laser element itself. It is attached. Therefore, even if the semiconductor laser element is sealed together with a rare gas that does not contain moisture, the moisture evaporating from the stem, cap, and the semiconductor laser element itself passes through the dielectric film due to the concentration gradient, and the semiconductor from the cavity end face Diffusion into the semiconductor stack of the laser element. The moisture in the dielectric film itself absorbs the laser light, and although the detailed mechanism is unknown, an absorption center is formed in the dielectric film to absorb the laser light. The absorbed laser light causes very high heat generation. It can be seen that, due to this heat generation, the end face portion of the semiconductor laser element becomes high in temperature, causing deterioration of the end face due to optical damage even if the light output is relatively low, and the semiconductor laser element is destroyed. From the above, it can be seen that preventing the diffusion of moisture from the dielectric film to the resonator end face is indispensable for improving the durability and reliability of the semiconductor laser device. However, when the entire sealing device is managed to have a low dew point in order to remove moisture, there is a demerit that the device becomes large and requires considerable costs.

Further, as disclosed in Patent Document 2, in the technique of forming a thin film made of SiN _x / SiO ₂ in direct contact with a semiconductor crystal, when the semiconductor crystal is a GaN-based crystal, oxygen in SiO ₂ Has been replaced with Ga, reacting very well at the interface, and causing deterioration of the end face. Even if the interface in contact with the GaN-based semiconductor SiN _x is formed, since SiN _x is thin inevitably as an optical film, oxygen and Ga is a problem of causing a substitution reaction passes through the SiN _x . On the other hand, when SiN _x as an optical film is thick and the semiconductor is a GaN-based crystal, there is a problem that cracks occur in the thick SiN _x and peeling occurs, and oxygen and Ga passing through them cause a substitution reaction. is there.

  In view of such a problem, the present invention forms a moisture absorption preventing film on the dielectric film on the laser light emitting side and reflecting side of the cavity surface of the nitride semiconductor laser element, and the dielectric film and the nitride semiconductor laminated body An object of the present invention is to provide a semiconductor element characterized by reducing diffusion of moisture into the inside.

  In order to achieve the above object, the present invention provides a nitride semiconductor multilayer body composed of a plurality of nitride semiconductor layers, two parallel end faces formed by cleaving the nitride semiconductor multilayer body, In a nitride semiconductor laser device including a coating film made of a dielectric material provided on each end face, a moisture absorption preventing layer is provided on any of the coating films.

  In the nitride semiconductor laser device having the above-described configuration, the moisture absorption preventing layer may be a nitride of C, Si, Ge, Sn, Ti, Zr, Hf, Rf, Y, Sr, Nb, and Ta. It consists of at least one.

  According to the present invention, in the nitride semiconductor laser element configured as described above, the moisture absorption layer is a single layer made of one of the nitrides.

  According to the present invention, in the nitride semiconductor laser element configured as described above, the moisture absorption layer includes a plurality of layers made of any of the nitrides.

  According to the present invention, in the nitride semiconductor laser element configured as described above, the moisture absorption preventing layer has a thickness of 10 to 100 mm.

  According to another aspect of the present invention, there is provided a nitride semiconductor laser device including the nitride semiconductor laser element configured as described above and a cap that covers the nitride semiconductor laser element, wherein the cap emits laser light emitted from the nitride semiconductor laser element. The nitride semiconductor laser element is in contact with the atmosphere outside the cap.

  If moisture is contained in the coating film provided on the end face of the nitride semiconductor laser element, an absorption center of the laser beam is formed in the coating film, and the coating film generates heat due to the absorption of the laser beam. Although the durability is reduced, according to the present invention, moisture contained in the atmosphere around the nitride semiconductor laser element and moisture evaporated from the surface of the stem, cap and nitride semiconductor laser element itself constituting the nitride semiconductor laser device It is possible to prevent the moisture absorption preventing layer from diffusing into the coating film and the nitride semiconductor laminated body, and to improve the durability of the nitride semiconductor laser device.

  In addition, according to the present invention, the moisture absorption preventing layer provided on the coating film of the nitride semiconductor laser element can prevent moisture from diffusing into the coating film or the like. There is no need to seal. Therefore, a hole that allows laser light to pass through may be provided in a cap that covers the nitride semiconductor laser element in the nitride semiconductor laser device, and a window made of glass or the like may not be provided. As a result, the manufacturing process of the nitride semiconductor laser device can be simplified while improving the durability of the nitride semiconductor laser element, and the material cost can be reduced because the cap structure can be simplified. Can do.

  Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a side view of a nitride semiconductor laser device according to an embodiment of the present invention, FIG. 2 is a plan view of the nitride semiconductor laser device, FIG. 3 is a cross-sectional view taken along the line AA in FIG. 5 is a perspective view of the nitride semiconductor laser device with the cap removed, and FIG. 6 is an external perspective view of the nitride semiconductor laser device.

As shown in FIG. 1, the nitride semiconductor laser element 10 has a nitride semiconductor multilayer body 20 formed on a GaN substrate 11. As shown in FIG. 2, a ridge portion 15 of an optical waveguide is formed on the nitride semiconductor multilayer body 20, and a p-electrode 13 is provided on the nitride semiconductor multilayer body 20 including the ridge portion 15. An n electrode 14 is provided on the surface of the GaN substrate 11 opposite to the surface on which the nitride semiconductor multilayer body 20 is formed (hereinafter referred to as the back surface). The nitride semiconductor laser element 10 includes a laser-side emission-side resonator end face 16 and a reflection-side resonator end face 17 formed by cleavage. Due to the resonator end faces 16 and 17, the nitride semiconductor multilayer body 20 operates as a resonator. An AR (anti-reflection) coating film 18 is formed on the emission-side resonator end face 16, and an HR (high-reflection) coating film 19 is formed on the reflection-side resonator end face 17. The AR coating film 18 consists of two layers of Al ₂ O ₃ / TiO ₂ , and the HR coating film 19 is Al ₂ O ₃ / SiO ₂ / TiO ₂ / SiO ₂ / TiO ₂ / SiO ₂ / TiO ₂ / SiO ₂ / It consists of 10 layers of TiO ₂ / SiO ₂ .

The structure of the nitride semiconductor multilayer body 20 will be described in detail. As shown in FIG. 3, the nitride semiconductor multilayer body 20 is formed on a GaN substrate 11 having a thickness of 100 μm, and has an n-type GaN layer 21 having a thickness of 0.2 μm and a thickness of 2.5 μm from the GaN substrate 11 side. N-type Al _0.05 Ga _0.95 N clad 22, 0.1 μm thick n-type GaN guide layer 23, 4 nm thick InGaN well layers, and 8 nm thick GaN barrier layers alternately. A stacked multiple quantum well active layer 24, a 20 nm thick p-type Al _0.3 Ga _0.7 N evaporation prevention layer 25, a 0.08 μm thick p-type GaN guide layer 26, and a 0.5 μm thick p-type layer. A type Al _0.062 Ga _0.938 N clad layer 27 and a p-type GaN contact layer 28 having a thickness of 0.1 μm are sequentially stacked. 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 GaN substrate 11 side. The p-type Al _0.062 Ga _0.938 N clad layer 27 and the p-type GaN contact layer 28 have the ridge portion 15 processed by vapor-phase etching and patterned by the insulating film 12 for current confinement.

Next, a method for manufacturing the nitride semiconductor laser element 10 will be described. First, the nitride semiconductor stacked body 20 is formed on the GaN substrate 11 from the n-type GaN layer 21 to the p-type GaN contact layer 28 in the order shown in FIG. Thereafter, the ridge portion is formed on the p-type GaN contact layer 28 and the p-type Al _0.062 Ga _0.938 N clad layer 27 by vapor phase etching such as RIE (Reactive Ion Etching) and ICP (Inductive Coupled Plasma). 15 is processed, and the insulating film 12 is formed on the upper surface of the nitride semiconductor stacked body 20 other than the upper surface of the p-type GaN contact layer 28 for current confinement. The insulating film 12 is made of SiO ₂ , ZrO ₂ or the like. Subsequently, the p-electrode 13 is formed, and the GaN substrate 11 is ground and polished from the back surface until the thickness of the GaN substrate 11 becomes about 100 μm. After the damage layer formed on the back surface of the GaN substrate 11 in this polishing process is removed by etching by vapor phase etching such as RIE, an n electrode 14 laminated in order of Ti / Al from the GaN substrate 11 side is formed by EB vapor deposition. Thus, the wafer 30 shown in FIG. 4 is completed.

  The wafer 30 is divided into bars to form a nitride semiconductor laser bar having a resonator end face. The division is performed at a scribe point 31 in a direction perpendicular to the longitudinal direction of the ridge portion 15. When the wafer 30 is divided into bars, the resonator end face formed by cleavage is exposed to the atmosphere, and contaminants such as moisture, natural oxide film, and carbon adhere to it. Therefore, in order to keep these contaminants from adhering to the end face of the resonator before forming the coating film, it is necessary to keep the vacuum state in the vapor deposition apparatus within several hours after the cleavage.

Next, an AR coat film 18 is formed on the emission-side resonator end face 16 of the nitride semiconductor laser bar by an EB vapor deposition apparatus. In the present embodiment, the AR coating film 18 is made of a dielectric film and has a two-layer structure of Al ₂ O ₃ / TiO _{2 in} order from the emission-side resonator end face 16 side.

AR coat film 18, first after the formation of the Al ₂ O ₃ using an Al ₂ O ₃ target, to form a TiO ₂ having a thickness of 17nm in an oxygen atmosphere using a Ti ₃ O ₅ targets. The thicknesses of these films are designed to have a front transmittance of 5% from the emission-side resonator end face 16 through the AR coat film 18 of light having a wavelength of 405 nm. The AR coating film 18 may be composed of a single layer of TiO ₂ or Al ₂ O ₃ , or may be composed of a single layer or a plurality of layers of other dielectric films.

Next, an HR coat film 19 is formed on the reflection-side resonator end face 17 of the nitride semiconductor laser bar. The HR coat film is made of a dielectric film, and in order from the reflection-side resonator end face 17 side, Al ₂ O ₃ / SiO ₂ / TiO ₂ / SiO ₂ / TiO ₂ / SiO ₂ / TiO ₂ / SiO ₂ / TiO _2. / SiO _{2 has} a 10-layer structure, and a multilayer coating of SiO ₂ / TiO ₂ plays a role as a basic reflective film. Further, the Al ₂ O ₃ film plays a role as a protective film for the multilayer coating of SiO ₂ / TiO ₂ .

SiO ₂ forming the HR coat film 19 is replaced with Ga of GaN on the reflection-side resonator end face 17 and reacts very well at the interface to cause deterioration of the end face. When TiO ₂ is in direct contact with GaN, the reaction causes light. Absorption and heat generation may cause deterioration of the film itself. Therefore, Al ₂ O ₃ which is stable against GaN is formed on the reflection-side resonator end face 17 as a protective film. In this embodiment, the thickness of Al ₂ O ₃ of the HR coat film 19 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. This is because 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, and when it is thicker than 100 mm, particularly when it is thicker than 200 mm, the reflectance is lowered. Note that Al ₂ O ₃ as a protective film is not necessarily provided.

In the present embodiment, a first moisture absorption prevention layer 41 and a second moisture absorption prevention layer 42 are formed on the AR coating film 18 and the HR coating film 19, respectively. The first moisture absorption prevention layer 41 and the second moisture absorption prevention layer 42 each have a two-layer structure of SiN / TiN in order from the coating films 18 and 19 side. A nitride semiconductor laser bar was held at about 150 ° C. in a nitrogen atmosphere, and Si and Ti ₃ O ₅ were used as targets, and each was formed to a thickness of 20 mm in the order of SiN / TiN. Here, the thickness of both SiN and TiN is preferably 10 to 100 mm. This is because, like many other dielectric films, when the thickness is less than 10 mm, it is difficult to form a uniform film and does not function as a moisture absorption preventing layer. Conversely, when the thickness exceeds 100 mm, it is difficult to obtain a uniform amorphous film in the film thickness direction, and light absorption is caused in a region that is partially crystallized out of the amorphous phase, leading to heat generation. In addition, as an apparatus for forming the first moisture absorption preventing layer 41, the second moisture absorption preventing layer 42, the AR coat film 18 and the HR coat film 19, an EB deposition apparatus, a sputter deposition apparatus, or the like is preferable.

  Next, the bar on which the coating films 18 and 19 are formed is divided into chips by scribing in a direction parallel to the longitudinal direction of the ridge portion 15 to form the nitride semiconductor laser element 10, and the submount 52 is shown in FIG. Mount with solder 53 on top. As the solder 53, AuSn, SnAgCu, or the like can be used. Next, the submount 52 on which the nitride semiconductor laser element 10 is mounted is mounted on the stem 51 through the mount 56 using solder (not shown) such as AuSn.

  A wiring 55 made of Au wire is used to connect the p-electrode 13 of the nitride semiconductor laser element 10 and the pin 54 of the stem 51, and the submount 52 and the mount 56, and as shown in FIG. The nitride semiconductor laser device 50 is completed by sealing together with the dry air with the cap 58 provided with. Laser light emitted from the nitride semiconductor laser element 10 is emitted to the outside through the glass window 59.

  The nitride semiconductor laser device 50 obtained in this way is provided with the first moisture absorption preventing layer 41 and the second moisture absorption preventing layer 42 in the nitride semiconductor laser element 10, whereby the coating film 18 which is a dielectric film. , 19 as well as moisture in the atmosphere and evaporated from the surfaces of the stem 51, the cap 58 and the nitride semiconductor laser device 10 itself to the GaN substrate 11 and the nitride semiconductor multilayer body 20 through the resonator end faces 16 and 17. It is possible to prevent the moisture that comes from diffusing. Therefore, it is possible to prevent the formation of the absorption center in the coating films 18 and 19, the heat generated by the absorbed laser light, and the deterioration of the resonator end faces 16 and 17 due to this heat generation. The durability, that is, the long-term reliability of the semiconductor laser device 50 can be improved.

  Further, even if there is moisture in the atmosphere or moisture evaporated from the surface of the stem 51 or the like, the moisture absorption preventing layers 41 and 42 can prevent the moisture from diffusing into the nitride semiconductor laser element 10. The nitride semiconductor laser element 10 does not need to be sealed with a rare gas or the like, and a cap 58 having a hole for emitting laser light and having no glass window 59 can be used. Therefore, noble gas used for sealing is not necessary, and there is a great merit in terms of manufacturing process steps of nitride semiconductor laser device 50 and material costs.

  In the present embodiment, the first moisture absorption preventing layer 41 and the second moisture absorption preventing layer 42 may not have the same structure. The moisture absorption preventing layers 41 and 42 are not limited to the above-described two-layer structure of SiN / TiN, and may be a single layer of SiN or TiN. Further, nitrides of group IV elements C, Si, Ge and Sn, and single layers of nitrides of metal elements Ti, Zr, Hf, Rf, Y, Sr, Nb and Ta, or these A plurality of single layers may be stacked. In the case of a plurality of layers, a plurality of layers made of the same material may be used.

An AR coating film composed of a single layer of Al ₂ O ₃ with a thickness of 80 nm designed for a reflectance of 5%, and SiO ₂ / TiO ₂ / SiO ₂ / TiO ₂ / SiO ₂ / TiO _{2 in this} order from the reflection-side resonator end face side. _The present invention comprises an HR coat film composed of 9 layers of ₂ / SiO ₂ / TiO ₂ / SiO ₂ , and a single layer of SiN is provided on both coat films as a first moisture absorption preventing layer and a second moisture absorption layer. The nitride semiconductor laser device having the above-described structure using such a nitride semiconductor laser element was subjected to an aging test by APC (Automatic Power Control) with an ambient temperature of 60 ° C., an output of 30 mW, and CW drive. As a comparative example, an aging test was also performed under the same conditions for a nitride semiconductor laser device using a nitride semiconductor laser element having the same AR coat film and HR coat film and having no moisture absorption preventing layer.

  First, FIG. 7 shows the result of measuring the change in Iop (driving current) accompanying aging for 30 nitride semiconductor laser elements of comparative examples. FIG. 7 is a graph in which the horizontal axis represents the aging time and the vertical axis represents Iop. Iop rises with a slight undulation, and most of the devices are destroyed in about 200 hours. Iop undulates because moisture gradually diffuses from the cavity end face to the inside of the nitride semiconductor stack, so that light absorption at the cavity end face increases, heat generation increases, element destruction progresses, and Iop rises. It is thought that it is because it is doing. In addition, when the resonator end face of the element after aging is measured with an SEM (Scanning Electron Microscope) or EDX (Energy Dispersive X-ray Spectroscopy), moisture is detected. It was.

  Next, FIG. 8 shows the result of measuring the change in Iop accompanying aging for 30 nitride semiconductor laser elements on which the moisture absorption preventing layers according to the present invention are formed. In FIG. 8, unlike in FIG. 7, no Iop wave is observed even after aging for 1000 hours or more. Therefore, it was found that the nitride semiconductor laser device according to the present invention has stable Iop even after aging for a long time, and has high durability and reliability for stable operation over a long period of time. This is presumably because the moisture absorption preventing layer prevented diffusion of moisture from the resonator end face into the nitride semiconductor multilayer body. Although details regarding this cause are not known, it is thought that the dense film quality peculiar to nitride contributes. Furthermore, the resonator end face of the element after aging was measured by SEM and EDX, but the moisture was below the detection limit.

  7 and 8, several Iops have not been flown at all since the beginning of aging, but this does not work at all. Appears with a certain probability even during manufacture.

The side view of the nitride semiconductor laser element concerning embodiment of this invention The top view of the nitride semiconductor laser element concerning embodiment of this invention AA sectional view of FIG. Three views of a wafer according to an embodiment of the present invention The perspective view of the nitride semiconductor laser device of the state which removed the cap concerning embodiment of this invention 1 is an external perspective view of a nitride semiconductor laser device according to an embodiment of the present invention. The graph which shows the change of Iop accompanying the aging of the nitride semiconductor laser element which has not formed the moisture absorption prevention layer The graph which shows the change of Iop accompanying the aging of the nitride semiconductor laser element concerning the Example of this invention which formed the moisture absorption prevention layer The graph which shows the change of the COD level accompanying the aging of the conventional nitride semiconductor laser element

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Nitride semiconductor laser element 11 GaN substrate 12 Insulating film 13 P electrode 14 N electrode 15 Ridge part 16 Output side resonator end face 17 Reflection side resonator end face 18 AR coat film 19 HR coat film 20 Nitride semiconductor laminate 21 n-type GaN layer 22 n-type Al _0.05 Ga _0.95 N clad 23 n-type GaN guide layer 24 multiple quantum well active layer 25 p-type Al _0.3 Ga _0.7 N evaporation prevention layer 26 p-type GaN guide layer 27 p-type Al _0.062 Ga _0.938 N-clad layer 28 p-type GaN contact layer 30 wafer 31 scribe point 41 first moisture absorption prevention layer 42 second moisture absorption prevention layer 50 nitride semiconductor laser device 51 stem 52 submount 53 solder 54 pin 55 wiring 57 pin 58 cap 59 glass window

Claims (6)

Nitride semiconductor laminate composed of a plurality of nitride semiconductor layers, two parallel end faces formed by cleaving the nitride semiconductor laminate, and a dielectric provided on the two end faces In a nitride semiconductor laser device comprising a coat film made of
A nitride semiconductor laser device, wherein a moisture absorption preventing layer is provided on any of the coating films.   The moisture absorption preventing layer is made of at least one of C, Si, Ge, Sn, Ti, Zr, Hf, Rf, Y, Sr, Nb and Ta nitrides. Nitride semiconductor laser device.   3. The nitride semiconductor laser device according to claim 2, wherein the moisture absorption layer is a single layer made of one of the nitrides.   The nitride semiconductor laser device according to claim 2, wherein the moisture absorption layer includes a plurality of layers made of any of the nitrides.   The nitride semiconductor laser device according to claim 1, wherein the moisture absorption preventing layer has a thickness of 10 to 100 mm. A nitride semiconductor laser device comprising the nitride semiconductor laser element according to claim 1 and a cap that covers the nitride semiconductor laser element.
The nitride semiconductor laser device, wherein the cap has a hole through which laser light emitted from the nitride semiconductor laser element passes, and the nitride semiconductor laser element is in contact with an atmosphere outside the cap.

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