JP2012178615A - Nitride semiconductor laser device, and manufacturing method of nitride semiconductor laser device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a nitride semiconductor light emitting device capable of being stably operated for a long period of time without causing voltage rise even when a nitride semiconductor laser element is operated in an Open-Air package, and to provide a manufacturing method thereof.SOLUTION: A nitride semiconductor light emitting device comprises: an n-type GaN substrate 101 which is a nitride semiconductor substrate and a nitride semiconductor layer including a p-type nitride semiconductor layer formed on the n-type GaN substrate 101. A protective film 113 including a silicon nitride film is formed above a current injection region formed in the p-type nitride semiconductor layer and composed of a p-type AlGaInN contact layer 108, a p-type AlGaInN clad layer 107 under the p-type AlGaInN contact layer 108 and a p-type AlGaInN layer 106.

Description

  The present invention relates to a nitride semiconductor laser device and a method for manufacturing a nitride semiconductor laser device.

  A conventional method for manufacturing a nitride semiconductor laser device will be described with reference to FIGS. FIG. 10 is a schematic view of the inside of a conventional nitride semiconductor laser device, and FIG. 11 is an external view of the conventional nitride semiconductor laser device.

  In the conventional method for manufacturing a nitride semiconductor laser device, after bonding the nitride semiconductor laser chip 403 to the heat dissipating submount 402 using the solder 406, the submount 402 to which the nitride semiconductor laser chip 403 is bonded is attached. It adhere | attaches on the holding | maintenance base | substrate (stem) 401 with solder (not shown). Then, the pin 405 formed on the holding base (stem) 401 and the nitride semiconductor laser chip 403 are electrically connected by a wire 404. Next, by removing moisture, for example, in a work box filled with air whose dew point is controlled to −20 ° C. or lower (hereinafter referred to as dry air), laser light is transmitted as shown in FIG. The nitride semiconductor laser chip was manufactured by sealing the nitride semiconductor laser chip together with dry air using the cap 407 with the glass lens 407a. The nitride semiconductor laser device manufactured in this way is operated in dry air.

JP 2000-114664 A

  Normally, when a nitride semiconductor laser device is operated in dry air, it can operate stably for 3000 hours or more. However, even when sealed with dry air, for example, the seal is not sufficient, and the dry air slightly leaks and the atmosphere (air containing moisture and air whose dew point is not controlled) enters the cap. It may enter. When air enters the cap in this way, a phenomenon in which the voltage rises greatly is observed in operation for about 100 to 1000 hours, including an element in which the voltage rises by 1 V or more, and further deterioration Some elements stop and stop oscillation.

  By the way, the nitride semiconductor laser chip 403 is not sealed with dry air by the cap 407, but in an air atmosphere, that is, in an air containing moisture and in which the dew point is not controlled (hereinafter referred to as OPEN-Air package). ), The same phenomenon as when dry air leaks and the atmosphere enters the cap is observed. Such a phenomenon is a phenomenon that has not been observed in GaAs laser elements that have been put into practical use, and is a phenomenon that is peculiar in nitride semiconductor laser elements. As described above, when the nitride semiconductor laser device is assembled or used, for example, when excessive stress is applied, a leak of dry air occurs, and the voltage increases when the atmosphere enters the cap. However, there is a problem of causing a failure.

  The present invention provides a nitride semiconductor laser device capable of operating stably for a long time without causing a voltage increase when the nitride semiconductor laser device is operated in an open-air package, and a method for manufacturing the same. With the goal.

  In order to solve the above problems, a nitride semiconductor light emitting device according to the first aspect of the present invention includes a nitride semiconductor substrate and a nitride semiconductor including a p-type nitride semiconductor layer formed on the nitride semiconductor substrate. The nitride semiconductor layer has a current injection region into which a current is injected, and a protective film made of a silicon nitride film and / or a silicon oxynitride film is formed above the current injection region It is characterized by being.

  In the nitride semiconductor light emitting device according to the first aspect, as described above, the protective film composed of the silicon nitride film and / or the silicon oxynitride film is formed above the current injection region. Even if the semiconductor light emitting device is operated in an air atmosphere, it is possible to suppress hydrogen contained in moisture in the air from reaching the current injection region. As a result, hydrogen can permeate and diffuse through the current injection region to increase the resistance of the current injection region and suppress an increase in the voltage of the nitride semiconductor light emitting device, so that it can operate stably for a long time. Can do.

  In the nitride semiconductor light emitting device according to the first aspect, preferably, an electrode and / or an electrode pad is formed above the current injection region, and the protective film is formed above the electrode and / or the electrode pad. ing. With this configuration, since the protective film is formed above the electrode and / or electrode pad, it is possible to effectively prevent the penetration of hydrogen contained in the moisture in the atmosphere. An increase in voltage of the light emitting element can be suppressed, and stable operation can be performed for a long time.

  In the nitride semiconductor light emitting device according to the first aspect, the current injection region may have a ridge stripe structure.

  A nitride semiconductor light emitting device according to a second aspect of the present invention includes a nitride semiconductor substrate, and a nitride semiconductor layer including a p-type nitride semiconductor layer formed on the nitride semiconductor substrate, and includes a p-type nitride. A protective film including a silicon nitride film and / or a silicon oxynitride film is formed over the semiconductor layer.

  In the nitride semiconductor light emitting device according to the second aspect, as described above, the protective film composed of the silicon nitride film and / or the silicon oxynitride film is formed above the p-type nitride semiconductor layer. Even if the nitride semiconductor light emitting device is operated in an air atmosphere, it is possible to suppress hydrogen contained in moisture in the air from reaching the p-type nitride semiconductor layer. As a result, it is possible to prevent the hydrogen from permeating and diffusing through the p-type nitride semiconductor layer, thereby increasing the resistance of the p-type nitride semiconductor layer and increasing the voltage of the nitride semiconductor light emitting device. It can operate stably over time.

  In the nitride semiconductor light emitting device according to the first and second aspects, the thickness of the silicon nitride film or the silicon oxynitride film is preferably 6 nm or more. If comprised in this way, it can suppress easily that hydrogen contained in the water | moisture content in air | atmosphere reaches | attains a nitride semiconductor layer.

In the nitride semiconductor light emitting device according to the first and second aspects, when the silicon oxynitride film is represented by the general formula SiO _1-x N _x , the nitrogen composition ratio x of the silicon oxynitride film is 0.1. The above is preferable. If comprised in this way, it can suppress easily that hydrogen contained in the water | moisture content in air | atmosphere reaches | attains a nitride semiconductor layer.

  According to a third aspect of the present invention, there is provided a method for manufacturing a nitride semiconductor light emitting device, comprising: forming a nitride semiconductor layer including a p-type nitride semiconductor layer on a nitride semiconductor substrate; and supplying a current to the nitride semiconductor layer. And a step of forming a current injection region into which silicon is implanted and a step of forming a protective film made of a silicon nitride film and / or a silicon oxynitride film above the current injection region. To do.

  Since the method for manufacturing a nitride semiconductor light emitting device in the third aspect includes a step of forming a protective film composed of a silicon nitride film and / or a silicon oxynitride film above the current injection region. Even if the obtained nitride semiconductor light emitting device is operated in an air atmosphere, hydrogen contained in moisture in the air can be prevented from reaching the current injection region. As a result, hydrogen can permeate and diffuse through the current injection region, thereby increasing the resistance of the current injection region and preventing the voltage from rising, and thus can operate stably for a long time.

  In the method for manufacturing a nitride semiconductor light emitting device according to the third aspect, preferably, a step of forming an electrode and / or an electrode pad above the current injection region, and a protective film above the electrode and / or the electrode pad And a forming step. If comprised in this way, since a protective film is formed above an electrode and / or an electrode pad, it can prevent effectively that hydrogen contained in the water | moisture content in air | atmosphere reaches | attains a current injection area | region.

  The nitride semiconductor light emitting device manufacturing method according to the third aspect may include a step of forming a ridge stripe structure in the nitride semiconductor layer so that the current injection region has a ridge stripe structure.

  According to a fourth aspect of the present invention, there is provided a method for manufacturing a nitride semiconductor light emitting device, comprising: forming a nitride semiconductor layer including a p-type nitride semiconductor layer on a nitride semiconductor substrate; And a step of forming a protective film composed of a silicon nitride film and / or a silicon oxynitride film.

  In the nitride semiconductor light emitting device manufacturing method according to the fourth aspect, as described above, the protective film composed of the silicon nitride film and / or the silicon oxynitride film is formed above the p-type nitride semiconductor layer. Since the process is included, even if the obtained nitride semiconductor light emitting device is operated in an air atmosphere, hydrogen contained in water in the air is prevented from reaching the p-type nitride semiconductor layer. Can do. As a result, hydrogen can permeate and diffuse through the p-type nitride semiconductor layer, so that the resistance of the p-type nitride semiconductor layer can be suppressed and the voltage can be prevented from rising. Can do.

  In the method for manufacturing a nitride semiconductor light emitting device according to the third and fourth aspects, preferably, the silicon nitride film or the silicon oxynitride film is formed so that the silicon nitride film or the silicon oxynitride film has a thickness of 6 nm or more. Process is included. If comprised in this way, it can suppress easily that hydrogen contained in the water | moisture content in air | atmosphere reaches | attains a nitride semiconductor layer.

In the method for manufacturing a nitride semiconductor light emitting device according to the third and fourth aspects, preferably, when the silicon oxynitride film is represented by the general formula SiO _1-x N _x , the nitrogen composition of the silicon oxynitride film A step of forming a silicon oxynitride film so that the ratio x is 0.1 or more is included. If comprised in this way, it can suppress easily that hydrogen contained in the water | moisture content in air | atmosphere reaches | attains a nitride semiconductor layer.

  As described above, according to the present invention, even when a nitride semiconductor light emitting device is operated in an air atmosphere (Open-Air package), it can operate stably for a long time without causing a voltage increase. A nitride semiconductor light emitting device that can be provided can be provided.

These are the perspective views of the nitride semiconductor laser chip concerning the 1st Embodiment of this invention. FIG. 2 is a schematic diagram of a nitride semiconductor laser device packaged using the nitride semiconductor laser chip shown in FIG. These are the aging test results of the nitride semiconductor laser element of Comparative Example 1. These are the aging test results of the nitride semiconductor laser device according to the first embodiment. These are figures which show the relationship between the thickness of the silicon nitride film which comprises the protective film of the nitride semiconductor laser element concerning 1st Embodiment, and a yield. These are the figures which expanded and showed a part of figure which shows the relationship between the thickness of the silicon nitride film shown in FIG. 5, and a yield. These are the perspective views of the nitride semiconductor laser chip concerning the 7th Embodiment of this invention. These are the perspective views of the nitride semiconductor laser chip concerning the 8th Embodiment of this invention. FIG. 2 is a schematic configuration diagram of an ECR sputtering film forming apparatus. FIG. 2 is a schematic view of the inside of a conventional nitride semiconductor laser device. FIG. 3 is an external view of a conventional nitride-based semiconductor laser device.

  Hereinafter, specific embodiments of the present invention will be described in detail with reference to the drawings.

<First Embodiment>
A first embodiment of the present invention will be described with reference to FIGS. 1 and 2. FIG. 1 is a perspective view of a nitride semiconductor laser chip according to the first embodiment of the present invention. FIG. 2 is a schematic view of a nitride semiconductor laser device packaged using the nitride semiconductor laser chip shown in FIG.

The nitride semiconductor laser device according to the first embodiment has a p-type nitride semiconductor layer, and this p-type nitride semiconductor layer includes at least an active layer and a cladding layer. The active layer and the cladding layer are a compound of at least one group 3 element selected from the group consisting of aluminum (Al), indium (In), or gallium (Ga) and nitrogen which is a group 5 element. And composed of a material mainly composed of a compound represented by the following general formula (1). Further, the p-type nitride semiconductor layer according to the first embodiment is doped with magnesium (Mg), beryllium (Be) or the like in the material represented by the following general formula (1). It is formed to show.
Al _k In _l Ga _m N (1)
In the formula (1), k is a positive number of 0 ≦ k ≦ 1, l is a positive number of 0 ≦ l ≦ 1, m is a positive number of 0 ≦ m ≦ 1, and k, l, m Satisfies k + 1 + m = 1.

Specifically, the nitride semiconductor laser device according to the first embodiment includes an n-type AlGaInN buffer layer 102 having a thickness of 0.2 μm and a thickness on the surface of an n-type GaN substrate 101 as shown in FIG. An n-type Al _0.05 Ga _0.95 InN cladding layer 103 having a thickness of 2.2 μm, an n-type AlGaInN guide layer 104 having a thickness of 20 nm, an 8 nm thick barrier layer made of InGaN, and a 5 nm thick well layer made of InGaN. 70 nm-thick AlGaInN multiple quantum well active layer 105 in which three layers are laminated so that the final layer formed on the p-type nitride semiconductor layer side is GaN, and a p-type having a thickness of 20 nm. and Al _0.3 Ga _0.7 InN layer 106, a p-type Al _0.05 Ga _0.95 InN cladding layer 107 having a thickness of 0.5 [mu] m, and p-type AlGaInN contact layer 108 having a thickness of 0.2μm is Laminated on, it is formed. The n-type GaN substrate is an example of the “nitride semiconductor substrate” in the present invention.

  The wavelength of the laser light oscillated from the nitride semiconductor laser element according to the present invention can be appropriately adjusted within a range of 350 nm to 480 nm, for example, depending on the mixed crystal ratio of the AlGaInN multiple quantum well active layer 105. In the first embodiment, adjustment is performed so that laser light having a wavelength of 405 nm oscillates.

  The p-type AlGaInN cladding layer 107 and the p-type AlGaInN contact layer 108 are partially removed to form a ridge stripe portion 111. That is, the other part of the p-type AlGaInN cladding layer 107 is removed so that a part thereof becomes a striped protrusion. The p-type AlGaInN contact layer 108 has other portions removed so that only the portion formed on the upper surface of the protruding portion formed in the p-type AlGaInN cladding layer 107 remains. In this way, the striped ridge stripe portion 111 is formed so as to extend in the resonator length direction (Y direction). In the first embodiment, the stripe width (X-direction width) of the ridge stripe portion 111 is 1.2 μm to 2.4 μm, and preferably about 1.5 μm.

Further, a p-type electrode 115 is provided on the upper surface of the p-type AlGaInN contact layer 108. The p-type electrode 115 is made of palladium (Pd) having a thickness of 50 nm formed so as to be in contact with the p-type contact layer 108. In addition, an insulating film 109 is provided on the upper surface of the p-type AlGaInN clad layer 107 in a portion excluding the portion where the ridge stripe portion 111 is formed. The insulating film 109 is formed so as to be in contact with the p-type AlGaInN cladding layer 107, and is formed by sequentially stacking silicon oxide (SiO ₂ ) having a thickness of 200 nm and titanium oxide (TiO ₂ ) having a thickness of 50 nm. It is composed of layers. Further, a p-type electrode pad 110 is formed on the upper surface of the p-type AlGaInN cladding layer 107 and the upper surface of the p-type electrode 115. The p-type electrode pad 110 is composed of two layers in which molybdenum (Mo) having a thickness of 20 nm and gold (Au) having a thickness of 200 nm are sequentially stacked from the insulating film 109 side.

  The nitride semiconductor laser device according to the first embodiment has a current injection region into which a current is injected into the nitride semiconductor layer. Generally, current is injected into the active layer region of the nitride semiconductor layer. That is, the current injection region is an active layer region into which current is injected. For example, in the ridge stripe type nitride semiconductor laser device as in the first embodiment, the p-type nitride semiconductor layer region immediately below the ridge stripe portion becomes the current injection region. That is, in the first embodiment, the active layer region which is a current injection region includes the p-type AlGaInN contact layer 108, the p-type AlGaInN cladding layer 107 under the p-type AlGaInN contact layer 108, and 106 portions of the p-type AlGaInN layer. It becomes. The current injection region emits light when current is injected. That is, the current injection region is also a light emitting region, and in the first embodiment, the active layer region immediately below the ridge stripe portion is the light emitting region.

  The nitride semiconductor light emitting device according to the present invention includes a silicon nitride film, a silicon oxynitride film, or a silicon nitride film over a current injection region, an electrode, an electrode pad, or an electrode and an electrode pad. And a protective film composed of a silicon oxynitride film. In the first embodiment, as shown in FIG. 1, a protective film 113 is formed on the upper surface of the p-type electrode pad 110. Thus, when the nitride semiconductor laser element including the p-type nitride semiconductor layer is operated in the atmosphere by forming the protective film 113, hydrogen contained in moisture in the atmosphere is converted into the p-type nitride semiconductor. Reaching the layer can be suppressed. As a result, it is possible to prevent the hydrogen from permeating and diffusing through the p-type nitride semiconductor layer, thereby increasing the resistance of the p-type nitride semiconductor layer and increasing the voltage.

  A wire bonding window 114 is formed in the protective film 113. The wire bonding window 114 is a window for bonding a p-type electrode pad 110 under the protective film 113 and a wire to be described later. Since the protective film 113 is an insulating film, if the entire surface of the p-type electrode pad 110 is covered, current cannot be injected by the wire.

  Further, an n-type electrode 112 is formed on the surface of the upper surface of the n-type GaN substrate 101 opposite to the layer stacking side. The n-type electrode 112 is formed so as to be in contact with the n-type GaN substrate 101, and has a hafnium (Hf) thickness of 30 nm, an aluminum (Al) thickness of 200 nm, and a molybdenum (Mo) thickness of 30 nm. And platinum (Pt) having a thickness of 50 nm and gold (Au) having a thickness of 200 nm.

  Next, a method for manufacturing the nitride semiconductor laser device according to the first embodiment will be described.

First, an n-type AlGaInN buffer layer 102 having a thickness of 0.2 μm is formed on an n-type GaN substrate 101 having a thickness of 450 μm (2-inch wafer) by using, for example, a MOCVD (Metal Organic Chemical Vapor Deposition) film forming apparatus. An n-type Al _0.05 Ga _0.95 InN cladding layer 103 having a thickness of 2.2 μm and an n-type AlGaInN guide layer 104 having a thickness of 20 nm are sequentially stacked to form a film.

Next, a layer composed of a barrier layer made of InGaN with a thickness of 8 nm and a well layer made of InGaN with a thickness of 5 nm is formed so that the final layer formed on the p-type nitride semiconductor layer side becomes GaN. Three layers are stacked to form an AlGaInN multiple quantum well active layer 105 having a thickness of 70 nm. Subsequently, a p-type Al _0.3 Ga _0.7 InN layer 106 having a thickness of 20 nm, a p-type Al _0.05 Ga _0.95 InN cladding layer 107 having a thickness of 0.5 μm, and a p-type AlGaInN contact layer 108 having a thickness of 0.2 μm are sequentially arranged. Laminate and form a film. Thereafter, palladium (Pd) having a thickness of 50 nm is formed on the p-type AlGaInN contact layer 108 by an electron beam (EB (Electron Beam)) vapor deposition method to form a p-type electrode 115.

  Next, in order to form the ridge stripe portion 111 by the photolithography process, a stripe mask is formed on the p-type electrode 115 and the p-type AlGaInN clad layer 107 is formed by using, for example, ICP (Inductively Coupled Plasma) etching method. The p-type electrode 115, the p-type AlGaInN contact layer 108, and the p-type AlGaInN cladding layer 107 are etched so that the depth becomes halfway. The etching depth is determined based on specifications required for the device. In the first embodiment, the etching is performed up to the bottom of the p-type AlGaInN cladding layer 107. In this way, the ridge stripe portion 111 is formed.

Next, 200 nm thick silicon oxide (SiO ₂ ) and 50 nm thick titanium oxide (TiO ₂ ) are formed on the upper surfaces of the ridge stripe portion 111 and the p-type AlGaInN clad layer 107 by EB vapor deposition or sputtering. ) Is formed. Then, after removing the ridge stripe mask formed on the p-type electrode 115 and the insulating film 109 by a lift-off method, the insulating film 109 side is formed above the insulating film 109 and the p-type electrode 115 by an EB vapor deposition method or the like. To 20 nm-thick molybdenum (Mo) and 200 nm-thick gold (Au) are sequentially stacked to form the p-type electrode pad 110.

  Next, a mask made of resist is formed in a portion where the wire bonding window 114 is formed on the upper surface of the p-type electrode pad 110 by a photolithography process. Subsequently, a protective film 113 is formed on the p-type electrode pad 110 by ECR (Electron Cyclotron Resonance) sputtering. In the first embodiment, the protective film 113 has a two-layer structure of a silicon nitride film and a silicon oxide film, a silicon nitride film is formed so as to be in contact with the p-type electrode pad, and a silicon oxide film is formed on the silicon nitride film. To do.

  Here, a method for manufacturing the protective film is described. The protective film can be formed by, for example, reactive sputtering such as ECR sputtering, CVD (Chemical Vapor Deposition), EB evaporation, or the like. In the first embodiment, the protective film is produced using ECR sputtering. A method for manufacturing a protective film by ECR sputtering will be described with reference to FIG. FIG. 9 is a schematic configuration diagram of an ECR sputtering film forming apparatus.

  The ECR sputtering method uses a plasma generated by ECR, applies a voltage to a target arranged around the plasma, and causes ions in the plasma to be accelerated and incident on the target, thereby generating and releasing a sputtering phenomenon. This is a method of forming a thin film by attaching target particles to the surface of a sample placed in the vicinity. In the present invention, a thin film formed on the surface of the sample serves as a protective film.

  As shown in FIG. 9, the ECR sputtering film forming apparatus includes a film forming chamber 300, a magnetic coil 303, and a microwave introduction window 302. A gas introduction port 301 and a gas exhaust port 309 are installed in the film formation chamber 300, and a target 304 and a heater 305 connected to an RF power source 308 are installed in the film formation chamber 300. A sample stage 307 is installed in the film formation chamber 300, and a sample 306 on which a thin film (protective film) is to be formed is installed on the sample stage 307. The magnetic coil 303 is provided for generating a magnetic field necessary for generating plasma, and the RF power source 308 is used for sputtering the target 304. Further, the microwave 310 is introduced into the film formation chamber 300 through the microwave introduction window 302.

  As the target 304 for forming the protective film according to the present invention, a silicon target or a silicon oxide target is used. For example, when a silicon nitride film is formed, a silicon target is installed as the target 304, nitrogen gas is introduced into the film formation chamber 300 from the gas introduction port 301 at a flow rate of 5.5 sccm, and plasma is generated efficiently. In order to increase the deposition rate, argon gas is introduced at a flow rate of 40.0 sccm. Then, a microwave necessary for plasma generation is applied, and a predetermined voltage is applied to the silicon target. Thereby, a silicon nitride film can be formed on the surface of the sample 306 installed on the sample table 307. Note that a silicon oxide film can be formed by introducing oxygen instead of introducing nitrogen into the growth chamber 300.

  On the other hand, in the case of forming a silicon oxynitride film, oxygen gas is introduced into a deposition chamber 300 in which a silicon target is installed, microwaves are applied to generate oxygen plasma, and the silicon target is exposed to oxygen plasma. Then, the silicon target is oxidized from the surface of the silicon target to a depth of several nanometers (step 1). Thereby, a target made of silicon oxide is produced temporarily. Next, nitrogen gas and argon gas are introduced into the film formation chamber 300, microwaves are applied to form a plasma state, and a target made of silicon oxide is sputtered, so that silicon oxynitride is applied to the sample placed on the sample stage 307. A film is formed (step 2). At this time, the oxygen content of the silicon oxynitride film can be changed by changing the gas ratio of nitrogen gas to oxygen gas.

However, as described above, in the case where a silicon oxynitride film is formed using a silicon target, when oxygen gas is introduced into the deposition chamber 300, the oxidization of silicon is high, so that the oxynitride with a low oxygen content is performed. When forming a silicon film, it becomes difficult to control the composition of oxygen and nitrogen, and the reproducibility tends to be low. In this case, a film formation chamber using silicon oxide having a low oxidation state represented by a composition formula of Si _p O _q (where 0 <p <1, 0 <q <0.67, p + q = 1) as the target 304. Oxynitridation with low oxygen content can be achieved by applying microwaves necessary for plasma generation while introducing only nitrogen gas without introducing oxygen gas into 300 and applying a predetermined voltage to the silicon oxide target. A silicon film can be formed relatively easily. Further, instead of using a target made of silicon oxide having a low oxidation state represented by the composition formula of Si _p O _q (where 0 <p <1, 0 <q <0.67, p + q = 1), oxygen The same effect can be obtained when using a target made of silicon oxynitride with a low content of.

  In addition to adjusting the oxygen and nitrogen contents in the silicon oxynitride film, that is, the composition ratio as described above, the degree of vacuum in the film formation chamber, the film formation temperature, or the degree of vacuum and film formation By changing film formation conditions such as both the temperature, the oxygen content in the silicon oxynitride film can be changed, and the composition of the silicon oxynitride film can be easily changed. Note that oxygen is more likely to be introduced into the silicon oxynitride film when the degree of vacuum in the deposition chamber is lower, and oxygen is less likely to be introduced into the silicon oxynitride film when the deposition temperature is higher.

  In addition, the inner wall of the film formation chamber is oxidized, or after silicon oxide is formed on the inner wall of the film formation chamber, argon gas and nitrogen gas are introduced into the film formation chamber, and a silicon target is used for sputtering. When the film is formed, oxygen on the inner wall of the film formation chamber is released by plasma, so that a protective film made of a silicon oxynitride film can also be formed. Note that when the target is sputtered using argon gas by the reactive sputtering method as described above, the produced protective film may contain a small amount (about 0% to 10%) of argon. Then, it can be applied to the nitride semiconductor light emitting device according to the present invention regardless of whether the produced protective film contains argon or not.

  In order to improve the adhesion between the nitride semiconductor layer, the electrode, or the electrode pad, and the protective film before forming the protective film, for example, nitridation is performed between step 1 and step 2 described above. The surface of the physical semiconductor layer, the electrode, or the electrode pad may be cleaned. Cleaning may be performed by heating, or cleaning may be performed by irradiation with argon plasma, nitrogen plasma, or mixed gas plasma of argon and nitrogen. Further, both cleaning by heating and cleaning by plasma irradiation may be performed in combination. When cleaning is performed by plasma irradiation, two-stage cleaning may be performed in which nitrogen plasma is irradiated after irradiation with argon plasma, or irradiation is performed in the reverse order. In addition to argon and nitrogen, a rare gas such as helium (He), neon (Ne), xenon (Xe), or krypton (Kr) may be used.

  As a cleaning method by heating, for example, a nitride semiconductor light-emitting element immediately before forming a protective film is placed in a film forming apparatus and heated at a temperature of 100 ° C. to 500 ° C. to form a nitride semiconductor layer or an electrode Alternatively, an oxide film or impurities attached to the surface of the electrode pad are removed. As a cleaning method by plasma irradiation, cleaning is performed by irradiating the surface of the nitride semiconductor layer, the electrode, or the electrode pad with argon plasma, nitrogen plasma, or the like. Further, plasma irradiation may be performed while heating. In addition, although the formation process of the protective film performed following cleaning is preferably performed in a state heated to a temperature of 100 ° C. to 500 ° C., the protective film may be formed without particularly heating.

  As a specific method of manufacturing the protective film according to the first embodiment, a silicon target is used as the target 304 in FIG. 9, and nitrogen gas is introduced from the gas inlet 301 into the film forming chamber 300 at a flow rate of 5.5 sccm. In addition, argon gas is introduced at a flow rate of 40.0 sccm in order to efficiently generate plasma and increase the deposition rate. Then, in order to sputter the silicon target, a 500 W RF power source 308 is applied to the silicon target, a 500 W microwave power necessary for plasma generation is applied, a film formation rate of 0.17 nm / second, and a wavelength of 633 nm. The protective film 113 has a two-layer structure made of a silicon nitride film having a light refractive index of 2.0 and a thickness of 500 nm and a silicon oxide film having a light refractive index of 1.4 and a thickness of 200 nm. Form.

  Then, after forming the protective film 113, the wire bonding window 114 is formed by removing the mask of the wire bonding window 114 and the protective film 113 by a lift-off method.

  Next, the n-type GaN substrate 101 having a thickness of 450 μm is ground and polished to obtain an n-type GaN substrate having a thickness of 130 μm. Subsequently, 30 nm-thick hafnium (Hf), 200 nm-thick aluminum (Al), and 30 nm-thickness molybdenum (on the surface opposite to the stacking side of each layer on the upper surface of the n-type GaN substrate 101 by the EB deposition method) Mo), platinum (Pt) with a thickness of 50 nm, and gold (Au) with a thickness of 200 nm are stacked in this order to form the n-type electrode 112.

Next, the disk-shaped wafer produced as described above is cleaved into a bar shape. In the first embodiment, the {1-100} plane is selected as the cleavage plane. Subsequently, a coat film is formed on the cleavage plane. Specifically, by an ECR sputtering method, an aluminum oxynitride layer (AlON) with a thickness of 20 nm, a silicon nitride film (SiON) with a thickness of 150 nm, and a thickness of 140 nm are in contact with the cleaved end surface on the light emission side. A laminated structure of an aluminum oxide layer (Al ₂ O ₃ ) is formed. On the other hand, an aluminum oxynitride layer (AlON) with a thickness of 20 nm, a silicon nitride film (SiON) with a thickness of 150 nm, and an aluminum oxide layer (Al ₂ O ₃ with a thickness of 140 nm) are in contact with the cleaved end face on the light reflection side. ), The silicon oxide film having a thickness of 71 nm and the titanium oxide film having a thickness of 46 nm are paired, and four pairs are stacked so that the outermost surface becomes a silicon oxide film. Then, a silicon oxide film is formed so as to have a thickness of 142 nm to form a highly reflective film. Thereafter, the bar-shaped element is divided into nitride semiconductor laser chips. In the present invention, a mirror surface (cleavage end face) formed by cleaving is defined as a resonator end face.

  Using the nitride semiconductor laser chip fabricated and chipped as described above for the nitride semiconductor laser chip 203 shown in FIG. 2, a nitride semiconductor laser device is fabricated. Specifically, the nitride semiconductor laser chip 203 is bonded to the heat dissipating submount (SiC) 202 using solder (gold tin) 206, and then the submount 202 to which the nitride semiconductor laser chip 203 is bonded is attached. Then, it is bonded onto the holding base (stem) 201 by solder (gold tin) (not shown). Thereafter, the pin 205 formed on the holding base (stem) 201 and the nitride semiconductor laser chip 203 are electrically connected by the wire 204. At this time, the wire 204 is connected to the wire bonding window 114 shown in FIG. 1 on the nitride semiconductor laser chip 203 side. That is, the p-type electrode pad 110 of the nitride semiconductor laser chip 203 and the pin 205 of the holding base (stem) 201 are connected by the wire 204.

  Next, an aging test of the nitride semiconductor laser device according to the first embodiment will be described with reference to FIGS. An aging test was performed using the nitride semiconductor laser device according to the first embodiment manufactured as described above, and the drive voltage when the nitride semiconductor laser chip 203 was operated in the OPEN-Air package was measured. We examined changes. The results are shown in FIG. 3 and FIG. FIG. 3 shows an aging test result of the nitride semiconductor laser element of Comparative Example 1 described later, and FIG. 4 shows an aging test result of the nitride semiconductor laser element according to the first embodiment.

(Comparative Example 1)
As a comparison with the nitride semiconductor laser device according to the first embodiment, a nitride semiconductor laser device in which the protective film 113 is not formed is manufactured and chipped as in the first embodiment. A semiconductor laser chip was formed. In the same manner as described above, the nitride semiconductor laser device of Comparative Example 1 was formed by mounting on a holding base (stem).

(Aging test)
An aging test was performed using the nitride semiconductor laser element according to the first embodiment and the nitride semiconductor laser element of Comparative Example 1. The aging test was performed under the conditions of an applied voltage of 10 mW and continuous (CW) driving in an air atmosphere at a temperature of 70 ° C. and a humidity of 20% to 40%. In the first embodiment, the aging test was performed using the nitride semiconductor laser element in the state shown in FIG. 2, that is, in the state where the cap is not attached.

As shown in FIG. 3, in the nitride semiconductor laser element of Comparative Example 1, there was an element in which V _op (operating voltage) increased by about 1 V in about 100 hours. On the other hand, in the nitride semiconductor laser device according to the first embodiment, as shown in FIG. 4, no device in which the V _op (operating voltage) increased was observed, and the device operated stably for 1000 hours or more. . From this result, it was found that even when the nitride semiconductor laser device is driven in an air atmosphere, the protective film 113 is formed, so that V _op (operating voltage) does not increase and can operate stably.

As described above, by forming the protective film 113, even when the nitride semiconductor laser element is operated in an air atmosphere, V _op (operating voltage) does not increase and can operate stably. The mechanism was considered as follows.

The air contains a lot of moisture (H ₂ O, —H group, —OH group) relative to dry air. Since the protective film is not formed in the nitride semiconductor laser element of Comparative Example 1, the hydrogen contained in the moisture in the atmosphere causes the p-type electrode pad 110 on the outermost surface of the nitride semiconductor laser element of Comparative Example 1 and The light passes through the p-type electrode 115 and diffuses. The diffused hydrogen reaches the insulating film 109 formed on the lower surface of the p-type electrode pad 110 and permeates and diffuses through the insulating film 109. Further, hydrogen is transmitted and diffused through the p-type AlGaInN cladding layer 107 and the p-type AlGaInN contact layer 108, and further transmitted and diffused through the p-type AlGaInN layer 106. As described above, when hydrogen diffuses into the p-type AlGaInN layer 106, the p-type AlGaInN cladding layer 107, and the p-type AlGaInN contact layer 108, the diffused hydrogen is contained in the Mg contained in at least one layer. It is thought that the resistance was increased by compensating the dopant.

On the other hand, since the protective film 113 is formed in the nitride semiconductor laser device according to the first embodiment, the hydrogen contained in the moisture in the atmosphere is different from the Si group of the silicon nitride film contained in the protective film. It is considered that the diffusion stays in the protective film due to bonding or the like and diffusion is suppressed. For this reason, hydrogen does not reach any of the p-type AlGaInN layer 106, the p-type AlGaInN cladding layer 107, and the p-type AlGaInN contact layer 108, and the resistance is increased by hydrogen compensating for the Mg dopant. It is thought that it can be suppressed. Thus, by forming the protective film 113 on the p-type nitride semiconductor layer where current injection is performed, an increase in V _op (operating voltage) due to the increase in resistance of the p-type nitride semiconductor layer is suppressed, and nitriding is performed. The semiconductor laser chip can be stably operated. Note that a voltage increase is more likely to occur when the p-type nitride semiconductor layer contains aluminum or when the aluminum content is higher.

  Next, the relationship between the thickness of the silicon nitride film constituting the protective film 113 according to the first embodiment and the yield will be described with reference to FIGS. FIG. 5 is a diagram showing the relationship between the thickness of the silicon nitride film constituting the protective film of the nitride semiconductor laser device according to the first embodiment and the yield, and FIG. 6 is a diagram of the silicon nitride film shown in FIG. It is the figure which expanded and showed a part of figure which shows the relationship between thickness and a yield.

(Sample preparation)
A nitride semiconductor laser chip was fabricated so that the silicon nitride film in the protective film 113 had a thickness of 1 μm to 500 μm, and a nitride semiconductor laser device was fabricated using the obtained nitride semiconductor laser chip.

(Aging test)
Using the nitride semiconductor laser element described above, an aging test was performed in an air atmosphere at a temperature of 70 ° C. and a humidity of 20% to 40% under an applied voltage of 10 mW and continuous (CW) drive conditions. Note that the aging test was performed in the state shown in FIG. 2, that is, in a state where no cap was attached, as described above.

(Yield evaluation)
As described above, an aging test was performed, and the yield of nitride semiconductor laser elements that did not cause a voltage increase after being driven for 1000 hours or longer was investigated.

As shown in FIG. 5, the yield tends to increase as the thickness of the silicon nitride film increases. Further, as shown in FIG. 6, when the thickness of the silicon nitride film was 6 nm, the yield was about 70%, and the yield was significantly increased. From this result, in order to operate the nitride semiconductor laser element stably for a long time, the thickness of the silicon nitride film is preferably 6 nm or more. When the thickness of the silicon nitride film is less than 6 nm, it is difficult to control the thickness because the thickness of the silicon nitride film is thin, and there is a possibility that a portion where the silicon nitride film is not formed may be generated. For this reason, hydrogen contained in moisture in the atmosphere can easily reach the p-type nitride semiconductor layer from a portion where the formation of the silicon nitride film is incomplete. As a result, hydrogen permeates and diffuses through the p-type nitride semiconductor layer, so that the resistance of the p-type nitride semiconductor layer is increased and the voltage is increased. Further, as shown in FIG. 5, in order to suppress the increase in V _op (operating voltage) of the nitride semiconductor laser element over 1000 hours and to operate stably for a long time, preferably the thickness of the silicon nitride film Is 80 nm or more, more preferably 300 nm or more. Note that although the thickness of silicon nitride in the protective film 113 has been described here, in the case of a silicon oxynitride film as well, an effect can be obtained when the thickness of the silicon oxynitride film is 6 nm or more.

<Second Embodiment>
Next, a second embodiment of the present invention will be described. In the second embodiment of the present invention, the nitride according to the second embodiment is used as the protective film 113b made of a single layer of a silicon oxynitride film (SiO _1-x N _x ) having a thickness of 500 nm. A semiconductor laser element was produced. As a result of Auger analysis of the protective film 113b, the composition ratio x of nitrogen of the protective film 113b (silicon oxynitride film (SiO _1-x N _x )) was 0.6. The nitride semiconductor laser device according to the second embodiment having such a protective film 113b was subjected to an aging test in the same manner as in the first embodiment. As a result, in the nitride semiconductor laser device according to the second embodiment, it was confirmed that, as in the first embodiment, no voltage increase due to aging was observed and the device could operate stably for a long time. In the second embodiment, the configuration is the same as that of the first embodiment except that the protective film 113 is changed to the protective film 113b.

<Third Embodiment>
Next, a third embodiment of the present invention will be described. In the third embodiment of the present invention, the protective film 113 includes a silicon oxynitride film with a thickness of 300 nm formed on the upper surface of the p-type electrode pad 110 and a film with a thickness of 120 nm formed on the upper surface of the silicon oxynitride film. A nitride semiconductor laser device according to the third embodiment was manufactured as a protective film 113c composed of two layers of a silicon oxide film. As a result of Auger analysis of the protective film 113c, the nitrogen composition ratio x of the silicon oxynitride film (SiO _1-x N _x ) contained in the protective film 113c was 0.8. An aging test was performed on the nitride semiconductor laser device according to the third embodiment having the protective film 113c in the same manner as in the first embodiment. As a result, it was confirmed that the nitride semiconductor laser device according to the third embodiment can operate stably for a long time without increasing voltage due to aging. In the third embodiment, the configuration is the same as that of the first embodiment except that the protective film 113 is changed to the protective film 113c.

<Fourth Embodiment>
Next, a fourth embodiment of the present invention will be described. In the fourth embodiment of the present invention, the protective film 113 includes a silicon oxide film having a thickness of 50 nm formed on the upper surface of the p-type electrode pad 110 and a silicon nitride film having a thickness of 300 nm formed on the upper surface of the silicon oxide film. A nitride semiconductor laser device according to the fourth embodiment was manufactured as a protective film 113d having two layers. An aging test was performed on the nitride semiconductor laser device according to the fourth embodiment having such a protective film 113d in the same manner as in the first embodiment. As a result, it was confirmed that the nitride semiconductor laser device according to the fourth embodiment could operate stably for a long time without an increase in voltage due to aging. In the fourth embodiment, the configuration is the same as that of the first embodiment except that the protective film 113 is changed to the protective film 113d.

<Fifth Embodiment>
Next, a fifth embodiment of the present invention will be described. In the fifth embodiment of the present invention, the protective film 113 includes a silicon oxide film with a thickness of 50 nm formed on the upper surface of the p-type electrode pad 110 and a nitride film with a thickness of 300 nm formed on the upper surface of the silicon oxide film. A nitride semiconductor laser device according to the fifth embodiment was manufactured as a protective film 113e composed of three layers of a silicon film and a 120 nm thick silicon oxide film formed on the upper surface of the silicon nitride film. An aging test was performed on the nitride semiconductor laser device according to the fifth embodiment having such a protective film 113e in the same manner as in the first embodiment. As a result, it was confirmed that the nitride semiconductor laser device according to the fifth embodiment could operate stably for a long time without an increase in voltage due to aging. In the fifth embodiment, the configuration is the same as that of the first embodiment except that the protective film 113 is changed to the protective film 113e.

<Sixth Embodiment>
Next, a sixth embodiment of the present invention will be described. In the sixth embodiment of the present invention, the nitride semiconductor laser element according to the sixth embodiment was manufactured by using the protective film 113 as a protective film 113f made of a single layer of a silicon nitride film having a thickness of 150 nm. An aging test was performed on the nitride semiconductor laser device according to the sixth embodiment having such a protective film 113f in the same manner as in the first embodiment. As a result, it was confirmed that the nitride semiconductor laser element according to the sixth embodiment also did not increase in voltage due to aging and could operate stably for a long time. In the sixth embodiment, the configuration is the same as that of the first embodiment except that the protective film 113 is changed to the protective film 113f.

<Seventh Embodiment>
Next, a seventh embodiment of the present invention will be described with reference to FIG. FIG. 7 is a perspective view of a nitride semiconductor laser chip according to the seventh embodiment of the present invention. In the seventh embodiment of the present invention, as shown in FIG. 7, a protective film 116 is formed on the entire ridge stripe portion 111 and in the vicinity of the ridge stripe portion 111 and on a part of the upper surface of the p-type electrode pad 110. Has been.

  An aging test was performed on the nitride semiconductor laser element according to the seventh embodiment in the same manner as in the first embodiment. As a result, it was confirmed that the nitride semiconductor laser element according to the seventh embodiment could operate stably with no voltage increase due to aging. From this result, it is considered that at least the ridge stripe portion 111 may be covered with a protective film in order to suppress a voltage increase due to aging and obtain a stable operation for a long time. The protective film 116 formed on the upper surface of the p-type electrode pad 110 is preferably formed so that the distance (d) between the end of the ridge stripe portion 111 and the end of the protective film 116 is 3 μm or more. . By forming the protective film 116 in this way, the nitride semiconductor laser device according to the seventh embodiment can be stably driven for a long time. In the seventh embodiment, the structure of the protective film 116 is the same as that of the first embodiment except that the structure of the protective film 116 is different from that of the protective film 113. The layer structure of the protective film 116 can be the same as the layer structure of the protective films 113 and 113b to 113f.

<Eighth Embodiment>
Next, an eighth embodiment of the present invention will be described with reference to FIG. FIG. 8 is a perspective view of a nitride semiconductor laser chip according to the eighth embodiment of the present invention. In the eighth embodiment of the present invention, as shown in FIG. 8, a protective film 117 is formed so as to cover a part of the ridge stripe portion 111 that is a current injection region and a part of the upper surface of the p-type electrode pad 110. Has been. That is, as shown in FIG. 8, the protective film 117 has a length (L2) in the resonator direction (Y direction) longer than the resonator length (L1) (the length of the ridge stripe portion 111 in the resonator direction). It is formed to be shorter.

  In the eighth embodiment, an aging test was performed on the nitride semiconductor laser element in which the length (L2) of the protective film 117 in the resonator direction (Y direction) was changed, as in the first embodiment. As a result, when L2 / L1 ≧ 0.3, no voltage increase due to aging was observed, and it was confirmed that the device could operate stably for a long time. In addition, the closer the L2 / L1 value is to 1, the greater the effect. Accordingly, if at least 30% or more of the ridge stripe portion 111 is covered with the protective film above the ridge stripe portion 111 that is the current injection region, an effect of suppressing a voltage increase due to aging can be obtained. The distance (d) between the end of the ridge stripe portion 111 and the end of the protective film 117 is preferably 3 μm or more. The eighth embodiment has the same configuration as that of the first embodiment except that the structure of the protective film 117 is different from that of the protective film 113. The layer structure of the protective film 117 can be the same as that of the protective films 113 and 113b to 113f.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  For example, in the first to eighth embodiments, the nitride semiconductor light emitting device has been described by using a nitride semiconductor laser device as an example. However, the present invention is not limited to this and is a nitride semiconductor light emitting diode device or the like. May be. In the first to eighth embodiments, the ridge stripe type nitride semiconductor laser element has been described as an example of the nitride semiconductor laser element. However, the present invention is not limited to this, and a surface emitting type is also possible. A nitride semiconductor laser element or the like may be used. In the surface-emitting nitride semiconductor laser element and the nitride semiconductor light-emitting diode element, the p-type nitride semiconductor layer region below the light transmissive electrode is called a current injection region, and the light extraction surface (light emitting surface) emits light. It becomes an area.

  In the first to eighth embodiments, the configuration using the GaN substrate as the nitride semiconductor substrate is shown as an example. However, the present invention is not limited to this, and an AlGaN substrate, an AlN substrate, or the like may be used. Good.

  In the first to eighth embodiments, the protective film is formed above the current injection region. However, the present invention is not limited to this, and the upper part of the p-type nitride semiconductor layer is used. Alternatively, a protective film may be formed. Even in such a configuration, when the nitride semiconductor light emitting element is operated in the atmosphere, it is possible to suppress the hydrogen contained in the atmosphere from reaching the p-type nitride semiconductor layer. Accordingly, since hydrogen penetrates and diffuses through the p-type nitride semiconductor layer, the p-type nitride semiconductor layer can be prevented from increasing in resistance and the voltage of the nitride semiconductor light-emitting element can be prevented from increasing. It can operate stably over time. At this time, the protective film formed above the p-type nitride semiconductor layer can have the same configuration as the protective film of the first to eighth embodiments.

In the second and third embodiments described above, the silicon composition ratio x of the silicon oxynitride film (SiO _1-x N _x ) constituting the protective film is 0.6 or 0.8. Although shown by way of example, the present invention is not limited to this, and the nitrogen composition ratio x of the silicon oxynitride film (SiO _1-x N _x ) is 0 <x ≦ 1, preferably 0.1 ≦ x ≦ 1, more preferably 0.4 ≦ x ≦ 1. As a method for measuring the nitrogen content, Auger analysis (AES) is used as an example, but EDX measurement (energy dispersive X-ray fluorescence analyzer) of TEM (transmission electron diffraction microscope) or the like may be used. In the present invention, the nitrogen composition ratio x in the silicon oxynitride film does not include argon or impurities contained in a sputtered film or the like when the silicon oxynitride film is formed, and is a ratio of the content of oxygen and nitrogen. Indicates the value obtained from.

  The protective film used in the present invention is not limited to the protective film shown in the first to eighth embodiments, and a silicon nitride film or a silicon oxynitride film may be laminated to form a multilayer structure. Alternatively, a multilayer structure in which a silicon nitride film and a silicon oxynitride film are stacked may be used. Note that in the case where a protective film having a multilayer structure is formed by stacking silicon oxynitride films, the oxygen content of the silicon oxynitride film in each layer (nitrogen) with respect to the thickness direction of the protective film, that is, the stacking direction of the nitride semiconductor layers (Content) may be formed differently, or the oxygen content (nitrogen content) of each layer may be changed stepwise. Examples of the protective film used in the present invention include protective films as shown in Table 1 in terms of adhesion to the electrode and stress. It should be noted that the same effect as described above can be obtained in any of the protective films having the layer structures shown in Table 1.

  Further, the protective film used in the present invention may include an insulating film such as silicon oxide as shown in the first and third to fifth embodiments. As shown in the sixth embodiment, an insulating film such as silicon oxide may not be included. In addition to silicon oxide, titanium oxide, silicon oxide, niobium oxide, tantalum oxide, zirconium oxide, or the like may be used.

  As the protective film used in the present invention, a silicon nitride film can be preferably used rather than a silicon oxynitride film. For example, when a silicon nitride film and a silicon oxynitride film having the same thickness are used, the greater the nitrogen content, the higher the effect of suppressing the voltage rise, and the higher the nitrogen content, the higher the voltage of the silicon nitride film. The suppression effect is great. That is, the silicon nitride film is thinner than the silicon oxynitride film and can obtain the same effect as the silicon oxynitride film.

  The silicon nitride film or silicon oxynitride film used in the present invention includes aluminum (Al), zirconium (Zr), hafnium (Hf), tantalum (Ta), niobium (Nb), titanium (Ti), and gallium. At least one or more additives selected from (Ga), vanadium (V), yttrium (Y) and the like may be added. At this time, the addition amount of the additive is preferably 10% or less of the silicon nitride film or the silicon oxynitride film.

  In the first to eighth embodiments, an electrode pad made of molybdenum (Mo) and gold (Au), a p-type electrode made of palladium (Pd), and hafnium (Hf). , An n-type electrode composed of aluminum (Al), molybdenum (Mo), platinum (Pt), and gold (Au) is shown as an example. However, the present invention is not limited to this, and the electrode pad and the electrode are What is necessary is just to be comprised from metal materials, such as nickel (Ni), palladium (Pd), gold (Au), platinum (Pt), molybdenum (Mo), aluminum (Al), and hafnium (Hf).

  In the first to eighth embodiments described above, the insulating film formed on the upper surface of the nitride semiconductor layer has been described using an insulating film made of silicon oxide and titanium oxide as an example. However, the present invention is not limited to this, as long as it is made of an insulating material such as aluminum oxide, titanium oxide, silicon oxide, niobium oxide, tantalum oxide, and zirconium oxide.

  Moreover, in the said 1st-8th embodiment, although the aging test was done in the state where the cap is not attached, in order to prevent the deterioration of the wire by aging, the cap without a lens is held as an object for wire protection. You may attach to a base | substrate by crimping | compression-bonding.

101 n-type GaN substrate (nitride semiconductor substrate)
102 n-type AlGaInN buffer layer 103 n-type Al _0.05 Ga _0.95 InN cladding layer 104 n-type AlGaInN guide layer 104
105 AlGaInN multiple quantum well active layer 106 p-type Al _0.3 Ga _0.7 InN layer 107 p-type Al _0.05 Ga _0.95 InN cladding layer 108 p-type AlGaInN contact layer 108
109 Insulating film 110 P-type pad electrode 111 Ridge stripe portion 112 N-type electrodes 113, 116, 117 Protective film 114 Wire bonding window 115 P-type electrodes 201, 401 Holding substrate (stem)
202, 402 Submount 203, 403 Nitride semiconductor laser chip 204, 404 Wire 205, 405 Pin 206, 407 Solder 407a Glass lens

Claims (5)

A nitride semiconductor laser device on which a nitride semiconductor laser chip is mounted,
The nitride semiconductor laser chip includes a nitride semiconductor substrate and a nitride semiconductor layer formed on the nitride semiconductor substrate and including a p-type nitride semiconductor layer, and the nitride semiconductor laser chip is sealed. Not
The nitride semiconductor layer has a current injection region into which a current is injected,
A nitride semiconductor laser device, wherein a protective film made of a silicon nitride film and / or a silicon oxynitride film is formed above the current injection region.   The electrode and / or electrode pad is formed above the current injection region, and the protective film is formed above the electrode and / or the electrode pad. Nitride semiconductor laser device.   The nitride semiconductor laser element according to claim 1, wherein the current injection region has a ridge stripe structure.   The nitride semiconductor laser element according to claim 1, wherein the silicon nitride film or the silicon oxynitride film has a thickness of 6 nm or more. A method of manufacturing a nitride semiconductor laser device on which a nitride semiconductor laser chip is mounted,
Forming a nitride semiconductor laser chip by laminating a nitride semiconductor layer including a p-type nitride semiconductor layer on a nitride semiconductor substrate;
Forming a current injection region into which current is injected into the nitride semiconductor layer;
Forming a protective film composed of a silicon nitride film and / or a silicon oxynitride film above the current injection region;
And the nitride semiconductor laser chip is not sealed. A method for manufacturing a nitride semiconductor laser device, comprising:

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