JPH11233896A - Manufacture of semiconductor light emitting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the deterioration of an end face by a method wherein compound semiconductor layers are grown in succession on a substrate and then end faces for a resonator are formed by cleaving and, after desorbing part of constituent elements near an end face of an active layer exposed on at least one end face of the resonator, an inactive layer is formed in a vacuum. SOLUTION: On inactive layers 14 formed on exposed end faces of a semiconductor, coating layers 15, 16 are formed which are dielectrics deposited in multilayers or a combination of a dielectric and a semiconductor. Preferably, irradiation of electron beams, heat rays and/or light beams on the end faces, formation of the inactive layers 14, and formation of the coating layers 15, 16 are conducted continuously in a vacuum. By this method, a light outputting efficiency from a semiconductor can be increased and the end faces can be also protected. Especially, for large output, a coating of a low refractive index against the oscillation frequency is applied onto the front end face and a coating of a high refractive index is applied onto the rear end face. By this method, the deterioration of the end faces can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a semiconductor light emitting device, particularly, a semiconductor laser. It is suitably used for semiconductor lasers for applications requiring compatibility. Also, an LED such as a super luminescent diode having a light emitting end formed by an end face can be applied to a surface emitting laser or the like.

[0002]

2. Description of the Related Art In recent years, progress in optical information processing technology and optical communication technology has been remarkable. For example, there is no shortage of high-density recording using a magneto-optical disk and two-way communication using an optical fiber network. For example, in the telecommunications field, Er ^{3+ is used} as an amplifier for signal amplification that has flexibility in the transmission system, as well as a large-capacity optical fiber transmission line corresponding to the future of the multimedia age.
Optical fiber amplifier (EDF) doped with rare earth such as
The research of A) is being actively conducted in various fields. And
It is an essential element as a component of EDFA,
Development of a semiconductor laser for a highly efficient excitation light source is awaited.

[0003] In principle, there are three types of oscillation wavelengths of an excitation light source that can be used for EDFA applications.
80 nm and 1480 nm. From the characteristics of the amplifier, it is known that pumping at 980 nm is most desirable in consideration of gain, noise, and the like. It is desired that such a laser having an oscillation wavelength of 980 nm satisfies the contradictory characteristics of a high output and a long life as an excitation light source. Wavelengths in the vicinity,
For example, at 890-1150 nm, an SHG light source,
There is also a demand as a heat source for a laser printer, and development of a laser with high output and high reliability is also straddled in various other applications.

In the information processing field, the output and wavelength of semiconductor lasers have been increasing for the purpose of high density recording, short time writing and reading, and high output has been achieved for conventional LDs having an oscillation wavelength of 780 nm. There is a strong demand, and the development of LDs in the 630-680 nm band is also being vigorously conducted in various fields. As an approach for achieving both high power and high reliability indispensable for realizing the laser, for example, the band gap of the active layer region near the end face is made transparent to the oscillation wavelength, and Various methods have been proposed to reduce the light absorption in the light. Lasers with these structures are generally window-structured lasers or NAMs (non Ab
This laser is called a sorbing mirror (structured laser) and is very effective when high power is required.

On the other hand, a solution to the problem as disclosed in Japanese Patent Application Laid-Open No. 3-101183 has been proposed. According to this, an end face without contamination is formed, and a substance which does not cause a reaction with the semiconductor end face or diffusion itself and does not contain oxygen is formed as a passivation layer or a part thereof. The manufacturing method is said to be effective. Further, as a known document similar to the above-mentioned JP-A-3-101183,
LWTuet al., (In-vacuum cleaving and coating
of semiconductor laser facets using silicon
and a dielectric, J. Appl. Phys. 80 (11) 1 DEC. 19
96). According to this, when the Si / AlO _x structure is coated on the laser end face and cleaved in a vacuum, the recombination rate of carriers at the cleaved face is reduced, and the initial CO 2
It is described that the D level rises.

Further, in order to reduce the electric field intensity at the light emitting end face of the semiconductor laser, Si is coated between the coating film and the semiconductor so that the antinode of the standing wave existing in the cavity direction does not coincide with the end face part. A technique of inserting a quarter wavelength into the interface is also known.

[0007]

For example, for a semiconductor laser having a wavelength of about 980 nm, a semiconductor laser capable of withstanding continuous use for about two years at an optical output of about 50-100 mW and a method of manufacturing the same have already been developed. The operation at the light output causes a rapid deterioration and the reliability is insufficient. The situation is the same for LDs in the 780 nm band and the 630-680 nm band, and securing reliability at high output is an issue especially for the entire semiconductor laser using a GaAs substrate.

[0008] One of the causes is caused by deterioration of an emission end face of a laser beam exposed to a very high light density. As is well known in GaAs / AlGaAs-based semiconductor lasers, there are many surface levels near the end face, but these levels absorb laser light.
In general, it is described that the temperature near the end face becomes higher than the temperature inside the laser, and this temperature rise further narrows the band gap near the end face, and further causes positive feedback such that laser light is more easily absorbed. This phenomenon is called end-face destruction, so-called COD (c
Known as atastrophic optical damage), sudden deterioration of the device due to a decrease in the COD level during a long-term energization test is a common problem in many semiconductor laser devices. Attempts to solve these problems have been made vigorously as described above, but are still technically insufficient.

Considering a conventional LD having a window structure, for example, there is a manufacturing method of epitaxially growing a semiconductor material transparent to an oscillation wavelength on a laser end face. In this method, since the laser is grown in a so-called bar state and epitaxial growth is performed on the end face, an electrode process performed thereafter becomes very complicated. Also, Zn
Alternatively, various methods have been proposed for disordering the active layer by intentionally thermally diffusing or implanting Si or the like as impurities into the active layer near the end face of the laser. These known documents are disclosed in JP-A-2-45992.
JP, JP-A-3-31083, JP-A-6-30
No. 2906 can be cited.

However, since impurity diffusion generally performed in the LD manufacturing process is performed from the epitaxial direction of the laser element toward the substrate, there is a problem in controllability of the diffusion depth and controllability of lateral diffusion with respect to the cavity direction. It is difficult to make stable production. In addition, in the case of ion implantation, high-energy ions are introduced from the end face, so that damage tends to remain on the LD end face even after annealing. In addition, an increase in reactive current due to a decrease in resistance in a region into which impurities are introduced has a problem that a threshold current and a drive current of a laser increase.

On the other hand, for example, Japanese Patent Laid-Open Publication No.
No. 3 discloses a non-contaminated end face, on which a reaction with the semiconductor end face or a substance which does not itself diffuse and does not contain oxygen is formed as a passivation layer or a part thereof. The technical problems of the manufacturing method are as follows. Generally, there is no effect of suppressing the generation of non-radiative recombination centers, such as Ga-O and As-O, which are generated on the end face at the time of cleavage, for example, in an atmosphere or the like, for example, in a clean room. As described in the first claim, in the specific method disclosed in the above-mentioned patent <Method of forming an end face without contamination>, it is indispensable to form a passivation layer in the cleaved in-situ, and this specific realization is possible. The only environment is cleavage in a vacuum as described in the tenth claim. However, this requires very complicated equipment and work compared to general cleavage in the atmosphere. Also,
Generally, the end face formed by dry etching disclosed in the eleventh to fourteenth claims forms more non-radiative recombination centers than the end face formed by cleavage, and is required to have a long life. It is not suitable as a method for producing an LD.

[0012] Although Si or amorphous Si is mentioned as the most suitable as the passivation layer, there is generally no substance which does not cause any diffusion at all, and it is assumed that the device is driven for a long time under high power and high temperature. In such a semiconductor laser, there is a concern about diffusion of the passivation material disclosed in the patent. In addition, LWTu et
al., (In-vacuum cleaving and coating of semi
conductor laser facets using silicon and a
In dielectric, J. Appl. Phys. 80 (11) 1 DEC. 1996), when the Si / AlO _x structure is coated on the laser end face by cleaving in a vacuum, the recombination rate of carriers at the cleaved face becomes slow. Although the initial COD level is raised, there is no description on long-term reliability, and no mention is made of the relationship between the coating and the LD structure.

Further, in order to reduce the electric field strength at the light emitting end face of the semiconductor laser, Si is coated between the coating film and the semiconductor so that the antinode of the standing wave existing in the cavity direction does not coincide with the end face part. In the technology of inserting a quarter wavelength into the interface, a wavelength band in which a general semiconductor laser is realized, particularly a high output LD is desired to be 400-1600n.
In m, since Si itself acts as a light absorber, a temperature rise at the end face may accelerate the deterioration of the device.

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and an object of the present invention is to stably suppress the interface state density at the end face of a semiconductor light emitting element such as a semiconductor laser for a long period of time, and furthermore, to achieve the above object. It is a realization of a simple manufacturing method that provides a semiconductor laser that operates stably even when diffusion of an activation layer during LD driving occurs.
This is nothing but to provide a high-performance semiconductor laser that achieves both high output and long life while suppressing degradation at the end face.

[0015]

Means for Solving the Problems The present inventors have made intensive studies to solve the above-mentioned problems, and as a result, have found that a compound containing a first conductive type clad layer, an active layer and a second conductive type clad layer on a substrate. In the method for manufacturing a semiconductor light emitting device having a semiconductor layer formed thereon and having a resonator structure, a compound semiconductor layer is sequentially crystal-grown on a substrate, and a resonator end face is formed by cleavage, and then at least one end face is formed. Exposed, at least some of the constituent elements near the end face of the active layer were desorbed by irradiation with heat rays, electron beams, light, etc., to create a region transparent to the oscillation wavelength near the end face of the semiconductor light emitting device. Later, the semiconductor light emitting device manufactured by the method of forming the passivation layer in a vacuum, despite the simple manufacturing method, to achieve both high output and long life at a level far beyond the conventional technology Find And it reached the present invention.

That is, the gist of the present invention is that a compound semiconductor layer including a first conductivity type clad layer, an active layer and a second conductivity type clad layer is formed on a substrate, and has a resonator structure. In the manufacturing method, a compound semiconductor layer is sequentially crystal-grown on a substrate, a cavity facet is formed by cleavage, and then at least one of the constituent elements exposed on at least one of the facets near the facet of the active layer is removed. A method for manufacturing a semiconductor light emitting device, characterized in that after desorption, a passivation layer is formed in a vacuum.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.
The method for manufacturing a semiconductor light emitting device according to the present invention is a semiconductor light emitting device having a resonator structure in which a compound semiconductor layer including a first conductivity type clad layer, an active layer and a second conductivity type clad layer is formed on a substrate. In the manufacturing method, a compound semiconductor layer is sequentially crystal-grown on a substrate, a resonator end face is formed by cleavage, and then exposed to at least one of the end faces.
A method for manufacturing a semiconductor light emitting device, comprising forming at least a passivation layer in a vacuum after desorbing at least a part of the constituent elements near the end face of the active layer, particularly the structure of the device or the like. Although not limited, one of the specific manufacturing methods is described below.
As an example, having a refractive index waveguide structure, the second conductivity type cladding layer is divided into a first layer and a second layer, and the second conductivity type second cladding layer and the current blocking layer form a current injection region. A case where a semiconductor laser having a structure having a contact layer for lowering contact resistance with an electrode is formed and the present invention is applied will be described.

A method for manufacturing a basic epitaxial structure of such a laser is described in, for example, Japanese Patent Application Laid-Open No. Hei 8-130344 by Horie et al.
This type of laser is used as a light source for an optical fiber amplifier used for optical communication and as a pickup light source for a large-scale magneto-optical memory for information processing, and includes an active layer and a cladding layer. Depending on the layer configuration such as the above and the material configuration, it can be further applied to various uses.

FIG. 2 is a schematic example in which a groove type semiconductor laser is formed as an example of the epitaxial structure in the semiconductor laser of the present invention. The substrate (1) may be made of InP, GaAs, GaN, InGa in view of a desired oscillation wavelength, lattice matching, distortion intentionally introduced into the active layer and the like.
A single crystal substrate such as As or Al ₂ O ₃ is used. Al ₂ O ₃
In some cases, a dielectric substrate can be used. As an embodiment of the present invention, an InP substrate or a GaAs substrate is preferable from the viewpoint of lattice matching with a III-V semiconductor light emitting device containing As, P, or the like as a V group, and includes As as a V group. Most preferably, a GaAs substrate is used.

A dielectric substrate such as Al ₂ O ₃ may be used for a material containing nitrogen or the like as a V group among III-V semiconductor light emitting devices. The substrate is not only a so-called just substrate, but also a so-called off-substrate (miss oriented su substrate) from the viewpoint of improving crystallinity during epitaxial growth.
bstrate) can also be used. This has the effect of promoting good crystal growth in the step flow mode and is widely used. The off-substrate having an inclination of about 0.5 to 2 degrees is widely used, but may have an inclination of about 10 degrees depending on the material system constituting the quantum well structure.

In some cases, the substrate is subjected to chemical etching, heat treatment, etc., in preparation for the fabrication of a light emitting device, utilizing a crystal growth technique such as MBE or MOCVD. The buffer layer (2) is preferably grown on the substrate to alleviate the incompleteness of the substrate bulk crystal and facilitate the formation of an epitaxial thin film having the same crystallographic axis. The buffer layer (2) is preferably made of the same compound as the substrate (1). When the substrate is GaAs, it is usually GaAs.
Is used. However, a superlattice layer is widely used as a buffer layer, and may not be formed of the same compound. On the other hand, when a dielectric substrate is used, a material different from that of the substrate may be appropriately selected depending on the desired emission wavelength and the structure of the entire device, instead of the same material as the substrate.

The first conductivity type cladding layer (3) is generally made of a material having a refractive index smaller than the average refractive index of the active layer (4), and is prepared to realize a desired oscillation wavelength. The material is appropriately defined by the substrate (1), the buffer layer (2), the active layer (4), and the like. For example, GaAs is used as the substrate (1), and when the buffer layer (2) is GaAs, an AlGaAs-based material, an InGaAs-based material,
aInP-based materials, InGaP-based materials, and the like are used. In some cases, the entire cladding layer may have a superlattice structure.

Although the effect of the present invention is effective irrespective of the conductivity type, material, structure, etc. of the active layer (4), it is preferable that the conductivity type is first P-type. As the P-type dopant, a known dopant such as Zn, C, Be, or Mg may be appropriately selected in consideration of the base material and the growth method.
e and / or C, most preferably Be. Generally, the band gap of a semiconductor is, for example, Heterostructure L
asers (HCCasey, Jr. MBPanish Academic Pres
As described in s 1978, p. 157), a substance having a higher hole concentration tends to be smaller. For example, GaAs
In the case of Eg, the bandgap is Eg (eV), and the P-type carrier concentration is P (cm ⁻³ ), indicating that Eg = 1.424-1.6 × 10 ⁻⁸ × P ^1/3. Have been. One feature of the present invention is that when a substance inserted as a passivation layer (14) between a laser end face and a dielectric interface diffuses during long-term laser driving, particularly during high-power operation, the n-type impurity is removed. Is gradually introduced into the active layer (4) or the like to cause an effective decrease in hole concentration due to the compensation effect. This means that the passivation layer (14) increases the band gap of the part where the constituent elements are diffused together with the LD driving, in the vicinity of the semiconductor end face, that is, the light absorption at the end face. It is expected to act to suppress. In this regard, a P-type active layer is desirable.

Further, from the viewpoint of material selection, the active layer (4) is preferably a system containing In and / or Ga, more preferably a system containing In, and most preferably a system containing In and Ga. This is a material system in which so-called ordering is liable to occur during crystal growth, and a substance inserted at the interface between the laser end face and the dielectric as a passivation layer (14) is formed as described above during long-term laser driving. This is because it is expected that when diffused, the disorder near the end face may be caused. Generally, disordering of the material causes an increase in the band gap, which, in combination with the compensation effect of the carrier, further suppresses the light absorption at the end face in the long term.

From these viewpoints, as the material of the active layer (4), specifically, an AlGaAs-based material, InGaAs
Materials, InGaP materials, AlGaInP materials, etc.
Among them, In _x Ga _1-x As (0 <x <1) or (Al _x
It is desirable to include Ga _1-x ) _y In _1-y P (0 <x, y <1), and it is particularly desirable to have a quantum well structure from the viewpoint of disordering. The choice of these materials is usually dictated by the desired oscillation wavelength.

Although the oscillation wavelength λ (nm) of the compound semiconductor light emitting device is substantially determined by the selection of the material of the active layer, the oscillation wavelength λ (nm) is preferably shorter than the Si absorption edge. The active layer (4) may be a normal bulk active layer composed of a single layer, but may have a single quantum well (SQW) structure, a double quantum well (DQW) structure, or a multiple quantum (MQW) structure. Etc. are adopted according to the purpose. In the quantum well structure, an optical guide layer is usually used in combination, and if necessary, a barrier layer is also used for separating the quantum well. The structure of the active layer includes a structure in which light guide layers are provided on both sides of the quantum well (SCH structure) and a structure in which the refractive index is continuously changed by gradually changing the composition of the light guide layer (GRIN-SCH). Structure) can be adopted. The material of the light guide layer is AlGa
As-based material, InGaAs-based material, InGaP-based material A
Selection can be made according to the active layer, such as an lGaInP-based material. Also, the light guide layer can be a superlattice combining the above materials.

On the other hand, Si is desirable as a specific material of the passivation layer (14). This is because, in general, an n-type dopant can be formed by diffusion from the (110) plane which forms a resonator in an edge-emitting device or the (100) plane which becomes an emission end in a surface-emitting laser or the like. And AlGaAs preferably used as a material for the active layer (4).
s-based material, InGaAs-based material, InGaP-based, AlG
This is because it is possible to disorder the aInP-based material.

A second conductive type first and second cladding layer (5);
(8), like the first conductivity type clad layer (3), is generally made of a material having a refractive index smaller than the average refractive index of the active layer (4), and the substrate (1) and the buffer layer (2). The material is appropriately defined by the active layer (4) and the like. For example, GaAs is used as the substrate (1), and when the buffer layer (2) is GaAs, an AlGaAs-based material, an InGaAs-based material, an AlGaInP-based material, an InGaP-based material, or the like is used.

FIG. 2 illustrates two types of etch stop layers (6) and (7) and a cap layer (10), which are employed in a preferred embodiment of the present invention and This is effective for accurately and easily creating a region. When the second etching stop layer (6) is made of, for example, _a material of Al _a Ga _1-a As (0 ≦ a ≦ 1), usually, GaAs is preferably used. This is because the second conductive type second cladding layer (8) and the like can be laminated with good crystallinity when regrowth is performed by the MOCVD method or the like, particularly, in the case of AlGaAs. The thickness of the second etching stop layer (6) is usually preferably 2 nm or more.

The first etching stop layer (7) is made of In _b G
A layer represented by a _1-b P (0 ≦ b ≦ 1) is preferable, and when GaAs is used as the substrate as in the present invention, b = 0.5 is usually used in a strain-free system. . The thickness of the first etching stop layer (7) is usually 5 nm or more, preferably 10 nm or more. If the thickness is less than 5 nm, etching may not be able to be prevented due to disorder of the film thickness or the like. On the other hand, depending on the film thickness, a strain system can be used, and b = 0, b = 1, and the like can be used.

The cap layer (10) is used as a protective layer for the current blocking layer (9) in the first growth and at the same time to facilitate the growth of the second conductive type second clad layer (8). Before the element structure is obtained, some or all of the elements are removed. Since it is necessary for the current blocking layer (9) to literally block the current and not substantially flow, the conductivity type is preferably the same as that of the first conductivity type cladding layer (3) or undoped. ,Also,
For example, when the current blocking layer (9) is formed of an AlGaAs system, the refractive index is lower than that of the second conductivity type second cladding layer (8) made of Al _y Ga _1-y As (0 <y ≦ 1). Is preferred. That is, the current blocking layer (9)
There If _{Al z Ga 1-z As (} 0 ≦ z ≦ 1), therefore it is preferable to become z> y As mixed crystal ratio.

The refractive index of the second-conductivity-type second cladding layer (8) is usually lower than that of the active layer (4). The second conductive type second clad layer (8) is usually the same as the first conductive type clad layer (3) and the second conductive type first clad layer (5). Further, as one preferred embodiment of the present invention, the second conductive type first clad layer (5), the second conductive type second clad layer (8) and the current blocking layer (9) are all made of the same material of the same composition. It is constituted by. In that case, an effective refractive index difference is formed by the first etching stop layer (7), and when the cap layer (10) is not completely removed, in addition to the first etching layer (7), the cap layer ( An effective refractive index difference is also formed by (10). By adopting such a layer configuration, it is possible to avoid various problems caused by mismatching of materials or compositions at respective interfaces of the second conductivity type second cladding layer (8) and the current blocking layer (9), Very preferred.

It is preferable to provide a contact layer (11) on the second conductive type second clad layer (8) for the purpose of lowering the contact resistivity with the electrode (12). The contact layer (11) is usually made of a GaAs material. In this layer, the carrier concentration is usually made higher than the other layers in order to lower the contact resistivity with the electrode. The buffer layer (2) generally has a thickness of 0.1 to 3 μm, the first conductivity type cladding layer (3) has a thickness of 0.5 to 3 μm, and the active layer (4) has a quantum well structure. 0.00 per layer
05 to 0.02 μm, second conductive type first clad layer (5)
The thickness of the second cladding layer (8) of the second conductivity type is 0.5 to 3 μm, and the thickness of the cap layer (10) is 0.05 to 0.3 μm.
Is selected from the range of 0.005 to 0.5 μm, and the thickness of the current blocking layer (9) is selected from the range of 0.3 to 2 μm.

The semiconductor light emitting device shown in FIG. 2 is constituted by further forming electrodes (12) and (13). Electrode (1
In the case of p-type, 2) is formed by sequentially depositing, for example, Ti / Pt / Au on the surface of the contact layer (11), followed by alloying. On the other hand, the electrode (13) is formed on the surface of the substrate (1).
It is formed by sequentially depositing uGe / Ni / Au and then performing an alloying process.

Although the semiconductor wafer thus formed is cleaved into a so-called laser bar state, the present invention does not always require a complicated cleavage step in a vacuum. This is because the absorption of the emission wavelength at the end face can be suppressed even in the cleavage at normal pressure in the air or in a nitrogen atmosphere. One of the techniques for this purpose is to desorb at least a part of the constituent elements near the end face of the active layer to make the active layer near the end face transparent to the oscillation wavelength.
As a specific means for this, a method of irradiating one end face with a heat ray having a fast thermal response, a method of irradiating an electron beam or light, or the like is effective.

As described above, the material of the active layer (4) is appropriately selected depending on the intended emission wavelength and output. For example, In _u Ga ₁ which is usually used to obtain an oscillation wavelength near 980 nm is used. _{In -u} As (0.15 ≦ u ≦ 0.35), the vapor pressure related to the re-evaporation of a group III arsenic compound in vacuum is InAs>GaAs> AlAs. For example, these mixed crystal semiconductors can selectively re-evaporate elements by selecting a heat treatment temperature.
In the case of InGaAs, InAs is selectively re-evaporated at a temperature of 500 ° C. to 650 ° C., and a region having a low In concentration is formed in the region subjected to the heat treatment by selective heating near the end face. Thereby, the band gap near the surface can be widened, and a so-called window structure is realized only near the end face.

The heat source to be irradiated, and in some cases, the light source may be any as long as it contains a wavelength that is absorbed by the material used for the active layer. Usually, a halogen lamp, a xenon lamp or the like is suitably used as both a heat source and a light source. The irradiation amount of the electron beam, the heat beam and / or the light beam may be appropriately adjusted so that the surface of the laser bar rises to a target temperature. In order to reduce the thermal load on the entire laser bar, the irradiation time is preferably as short as possible, usually 10 minutes or less, and more preferably 5 minutes or less. This process is performed in a vacuum, and the degree of vacuum is 10 ⁻³ To
rr or less, preferably 10 ^-4 Torr or less, and most preferably 10 ^-7 Torr or less.

In these methods, since the end face processing can be performed after the electrodes are formed, in other words, the electrodes can be formed on the wafer before cleavage. This is overwhelmingly advantageous in manufacturing since a complicated process of forming electrodes on each of the subsequent laser bars is not required. As a material capable of performing such a treatment, the AlGaAs-based material described above,
InGaAs-based material, InGaAsP-based material, InGa
An AlP-based material or the like can be mentioned, preferably a material containing In and Ga, and most preferably InxGa1-xAs (0 <x
In the vicinity of 980 nm having an active layer made of a material containing In, Ga and As as in <1), that is, 890 to 1200
It works suitably for a semiconductor laser having an emission wavelength of about nm.

The formation of the transparent region by the processing near the end face is combined with the effect of expanding the band gap near the end face while the passivation layer (14) is diffused during driving of the LD. This realizes a long-life element. Further, the desorption of the end face constituent elements due to heat and light irradiation is a secondary step of removing oxides and nitrides that are generated when the wafer is cleaved in the air or in a nitrogen atmosphere and become non-radiative recombination centers. There is also a positive effect. A first conductivity type cladding layer (3), an active layer (4), a second conductivity type cladding layer (5),
(8) Among the elements that are constituent elements of the substrate (1), the current blocking layer (9), the contact layer (11), and the like exposed at the end face, among the elements located near the resonator mirror, By removing at least one of the oxides and / or nitrides, particularly those present in an oxide state, a semiconductor light emitting device with higher output and longer life can be obtained.

As a method for analyzing whether at least one of the constituent elements does not exist in the form of an oxide, for example, XPS (X-ray Photo-electron Spectr
oscopy X-ray photoelectron spectroscopy). This is a very useful tool for knowing the chemical bonding state of each element.
By irradiating the laser end face with X-rays having a size of about μm × 100 μm, and photo-electrons generated as a result of the energy spectroscopy, the chemical bonding state of each element constituting the laser end face can be confirmed. At this time, by changing the angle between the photoelectron detector and the sample surface, it is possible to easily obtain only information near the surface. In addition, since a general laser is coated on its end face with a dielectric or a dielectric and semiconductor pair as described later, various etching methods are used before the XPS measurement to a thickness suitable for analysis. Usually, the coating film is thinned. Further, with respect to a laser on which a thin coating film of about 2 nm is formed, it is possible to analyze the end face of the semiconductor laser without performing such processing as etching.

Cleavage is preferably used for forming the end face. This is widely used in the case of an edge-emitting laser, but there are also cases where a resonator is formed during the crystal growth process like a surface-emitting laser.

The end face formed by cleavage varies depending on the orientation of the substrate used. For example, when forming an element such as an edge emitting laser using a substrate having a crystallographically equivalent surface to the nominally (100) (nominally (100)) preferably used, (110) or The plane crystallographically equivalent to this is the plane that forms the resonator, but when the above-mentioned off substrate (miss oriented substrate) is used, depending on the relationship between the tilted direction and the resonator direction, the end face May not form 90 ° with the resonator direction. For example, when a substrate whose angle is inclined by 2 ° from the (100) substrate toward the (1-10) direction is used, the end face is also inclined by 2 degrees.

In the present invention, the passivation layer is formed on the end face of the compound semiconductor light emitting device, and forms a non-radiative recombination center when the elements constituting the end face are combined. This layer prevents chemical reactions. The passivation layer is formed so as to cover at least the first conductivity type clad layer, the active layer and the second conductivity type clad layer which form the end face, but is usually formed so as to cover the entire end face. .

In the present invention, the passivation layer is formed by irradiating the end face with plasma in a vacuum, and subsequently in a vacuum, ie, 10 μm.
^The film is formed in a vacuum of about ^-3 Torr or less, preferably in a high vacuum of about 10 ^-6 Torr or less, and most preferably in a vacuum of about 10 ^-7 Torr or less. As a material of the passivation layer, Si, Ge,
Among them, S, Se and the like can be mentioned. Among them, it is preferable to include Si, and it is preferable to include 50 at% or more of Si in the passivation layer.

The element attached to the semiconductor end face as the passivation layer (14) is preferably an element which becomes an n-type impurity when diffused into the active layer. Preferably, Si is used as described above. Although the structure and characteristics of Si differ crystallographically depending on the manufacturing method, the effect is recognized in any of single crystal, polycrystal and amorphous. Particularly preferably, amorphous Si formed at a low film formation rate in a high vacuum is used. In general, the absorption edge of Si differs depending on the film quality, but it is considered that the absorption edge is transparent for a wavelength of about 2 μm or more and does not absorb. Conversely, for wavelengths shorter than about 2 μm, the refractive index N of Si is N = n + ik, where n is the real part of the refractive index, k is the extinction coefficient, and n is about 3.5.

Generally, the thickness T of the passivation layer (14)
It is desirable that _p (nm) is thicker than 0.2 (nm).
However, on the other hand, an extremely thick film thickness, for example, 100 nm may not be suitable. The desirable thickness of the passivation layer (14) is defined by the lower limit based on the requirement that the passivation layer itself exists as a film, and the upper limit is defined by the fact that light emitted from the active layer is Si.
It is determined by the balance with the effect absorbed by. That is, the requirement that the end face be entirely covered with the passivation film and the effect of both sides such as the temperature rise of the end face due to the absorption of Si can be considered when Si is deposited on the end face. According to the experimental results, 0.2 (nm) <T _p (nm) <λ / 8n (nm) (I) (where, in the formula (I), λ is the oscillation wavelength of the semiconductor light emitting element. And n represents the real part of the refractive index at the wavelength λ of the passivation layer.) However, 0.2n
The effect has been confirmed even when the thickness is less than m.

Further, on the passivation layer (14) formed on the exposed semiconductor end face, a coating layer (1) made of a laminated dielectric or a combination of a dielectric and a semiconductor is formed.
5) It is important to have (16). Particularly preferably, the end face is irradiated with an electron beam, a heat ray and / or a light beam, the passivation layer (14) is formed, and the coating layer (15) is formed.
The formation of (16) is continuously performed in a vacuum. This is mainly performed for the two purposes of increasing the efficiency of extracting light from the semiconductor laser and further protecting the end face. Particularly, in order to obtain a high output, an asymmetric coating is widely used, in which a coating having a low reflectance with respect to the oscillation wavelength is applied to the front end face, and a coating having a high reflectance is applied to the rear end face.

Various materials can be used for the coating, such as AlO _x , TiO _x , SiO _x , SiN,
It is preferable to use one or two or more selected from the group consisting of Si and ZnS. However, as the low reflection coating, AlO _x, TiO _x , SiO _{x and the} like are used, and as the high reflection coating, AlO _x / Si is used. Multilayer film, TiO _x / S
An iO _x multilayer film or the like is used. Each film thickness is adjusted to achieve a desired reflectance. However, generally, AlO _x , TiO _x , S
In general, iO _{x and the} like are adjusted so that the film thickness is in the vicinity of λ / 4n, where n is the real part of the refractive index at the wavelength λ. In addition, the high reflection multilayer film is also adjusted so that each material constituting the high reflection multilayer film is in the vicinity of λ / 4n, and it is preferable to stack this pair according to the purpose.

In the method of producing the coating layers (15) and (16), a so-called IAD (Ion Assisted Depositio) is used.
The n) method is preferably used. This is a method in which ions having a certain energy are irradiated simultaneously with the vacuum deposition of the coating material, and ion irradiation with a rare gas is particularly preferable. Further, among rare gases, IAD by Ar ions has a great effect on improving the film quality of the coating material. In particular, the optimal condition for Ar ion irradiation is 25 e
V to about 300 eV, more preferably 50 eV to 2
This is to be used in a low energy range of about 00 eV, whereby coating can be performed without damaging the semiconductor end face. In addition, it is preferable to perform the treatment in a vacuum of about 10 ⁻³ Torr or less, more preferably about 10 ⁻⁴ Torr or less, and most preferably about 10 ⁻⁵ Torr or less.

[0050]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to the following examples unless it exceeds the gist of the present invention. Example 1 A groove type laser device shown in FIG. 2 was manufactured as follows.

N-type Ga having a carrier concentration of 1 × 10 ¹⁸ cm ^-3
Buffer layer (2) on As substrate (1) by MBE method
N-type GaAs layer having a carrier concentration of 1 × 10 ¹⁸ cm ^{−3 having} a thickness of 1 μm, and n having a carrier concentration of 1 × 10 ¹⁸ cm ^{−3 having} a thickness of 1.5 μm as a first conductive type cladding layer (3).
Type Al _0.35 Ga _0.65 As layer, then a 6 nm thick undoped In _0.2 Ga _0.8 As single quantum well (SQW) on a 30 nm thick undoped GaAs light guide layer, and then a 30 nm thick undoped GaAs The active layer (4) having a light guide layer and the second conductive type first clad layer (5) have a thickness of 0.1 μm and a carrier concentration of 1 × 10 ^18.
cm ⁻³ p-type Al _0.35 Ga _0.65 As layer, 10 nm thick as second etching stop layer (6), carrier concentration 1 × 1
0 ¹⁸ cm ^-3 p-type GaAs layer, 20 nm thick as first etching stop layer (7), carrier concentration 5 × 10 ¹⁷ c
m ⁻³ n-type In _0.5 Ga _0.5 P layer, current blocking layer (9)
Thickness 0.5 μm, carrier concentration 5 × 10 ¹⁷ cm ⁻³
N-type Al _0.39 Ga _0.61 As layer, n as a cap layer (10) having a thickness of 10 nm and a carrier concentration of 1 × 10 ¹⁸ cm ⁻³ .
GaAs layers were sequentially stacked.

Next, a mask of silicon nitride was provided on the portion except for the current injection region on the uppermost layer. In this case, the width of the opening of the silicon nitride mask was 1.5 μm. First
Etching was performed using the etching stopper layer as an etching stop layer, and the cap layer (10) and the current block layer (9) in the current injection region were removed. The etchant used at this time was sulfuric acid (98 wt%), hydrogen peroxide (30 wt%).
% Aqueous solution) and water at a volume ratio of 1: 1: 5, and performed at 25 ° C. for 30 seconds.

Next, HF (49%) and NH ₄ F (40
%) In an etching solution mixed at a ratio of 1: 6 to remove the silicon nitride layer for 2 minutes and 30 seconds, and further etch the first etching stop layer in the current injection region using the second etch stop layer as an etch stop layer. Removed. The etchant used at this time was hydrochloric acid (35 wt%) and water:
1, and the temperature was 25 ° C. and the time was 2 minutes.

Thereafter, a carrier concentration of 1 × 10 ¹⁸ cm ^{−3 is formed} as a second conductivity type second cladding layer (8) by MOCVD.
The p-type Al _0.35 Ga _0.65 As layer is grown to a thickness of 1.5 μm at the buried portion (current injection region),
Finally, as a contact layer (11) for maintaining good contact with the electrode, a thickness of 7 μm and a carrier concentration of 1 × 10 ¹⁹
A p-type GaAs layer of cm ⁻³ was grown to form a laser device. The width W of the current injection region of this laser element, that is, the width of the second conductive type second clad layer at the interface with the second conductive type first clad layer was 2.2 μm.

An n-type electrode is placed on the substrate side of the wafer.
AuGeNi / Au as the pole (13) and the p-side
Electrode (12) is Ti / Pt / Au deposited at 400 ° C.
And completed the wafer. Then in the atmosphere
Then, it is cleaved into a laser bar with a cavity length of 700 μm.
To expose the (110) plane and hold the Ar plasma generator.
A laser bar was placed inside the vacuum chamber. here
First, a 4.5 KW halogen output was applied to the front end face (cleavage face).
1 × 10 using a lamp^-6Heat rays and rays in Torr vacuum
For 3 minutes. In this case, the temperature of the end face of the laser bar is
It was about 550 degrees. Furthermore, 2 × 10^-7Torr vacuum
Deposited amorphous Si passivation layer on 2nm end face
And continuously use AlO _xOscillation wavelength 98
At 0 nm, the front end face has a reflectivity of 2.5%.
A 165 nm film was formed. AlO_x4 × 10 during film formation^-FiveTor
average energy 120 eV, current density 20 in vacuum r
0 μA / cm^TwoSupply of the Ar plasma to the end face of the raw material
Irradiated simultaneously.

In order to further process the rear end face, the laser bar was once taken out of the vacuum chamber. To perform the same processing on the rear end face side as on the front end face side, 1 × 10 ⁻⁶ Torr using a 4.5 KW halogen lamp.
Irradiate heat rays and light rays for 3 minutes in a vacuum of 2.
Amorphous Si passivation layer in vacuum at 10 ^-7 Torr
nm. 4 × 10 ^-5 Torr continuously
170 nm / amorphous Si the AlO _x film in vacuum
60 nm / AlO _x film 170 nm / amorphous S
The four coating layers where i was 60 nm
O _x film is IAD method, amorphous Si was prepared rear end face of the formed reflectance 92% by electron beam evaporation.

It has been confirmed that the real part of the refractive index of amorphous Si at 980 nm is about 3.4.

From the laser bar, 10 devices were mounted on a submount for heat radiation and packaged in a nitrogen atmosphere. As the average initial characteristics of the device, the threshold current was 21 mA at 25 ° C., and kink was observed at 350 mA and 250 mW. The oscillation wavelength of the device was 980 nm. FIG. 3 shows the results of a life test performed on this group. As a result of an acceleration test at 150 mW 70 ° C., 10
There was no sudden death at the time of 00hs, and a stable operation was confirmed.

One sample of this laser bar was subjected to XPS measurement for end face analysis. At this time, the take-out angle of the photoelectrons was set to 75 degrees, and the state of the end face of the semiconductor laser was observed. As a result, GaAs normally exposed once to the atmosphere
Neither Ga-O nor As-O existing on the s (110) plane was detected at all. Also, one device was taken out of the laser bar as a sample for analysis, and A at the front end face was taken.
After removing the lO _x layer and the Si layer with a hydrofluoric acid-based etchant, the layer was placed in a vacuum analyzer, and the band gap near the front end face of the active layer was measured using electron energy loss spectroscopy. Since electron energy loss spectroscopy is an analysis method that obtains information only near the sample surface (maximum analysis depth of about 1.5 nm), it is a powerful method for measuring the band gap of the laser end face without being affected by the physical properties of the bulk region. It is an effective method. When an electron beam of 1000 eV focused on about 100 nmφ is irradiated to the vicinity of the active layer on the laser end face, the energy of the loss electron diffracted from the area of 1 nm deep from the end face of the semiconductor itself behind the surface oxide layer is analyzed. From the loss peak due to the inter-transition, the band gap at the end face of the InGaAs active layer was 1.45 eV. The energy gap between the quantum levels of the InGaAs quantum well active layer at room temperature determined by photoluminescence measurement was 1.29 e.
V, and it was confirmed that the band gap near the end face was widened due to the effect of the desorption of InAs mainly in the active layer, and the end face was transparent to the oscillation wavelength. (Embodiment 2) Using the same wafer structure as in Embodiment 1, the processing of the laser end face was changed as follows.

The laser bar was cleaved in the atmosphere into a laser bar having a cavity length of 700 μm, and the laser bar was placed in a vacuum chamber having an Ar plasma generator. Here, first, using a 4.5 KW halogen lamp on the front end face,
Heat rays and light rays were irradiated for 3 minutes in a vacuum of 1 × 10 ⁻⁶ Torr. At this time, the end face temperature of the laser bar was about 550 degrees. Further, an amorphous Si passivation layer is continuously deposited on a 3 nm end face in a vacuum of 2 × 10 ⁻⁷ Torr, and an AlO _x film is continuously formed as a coating layer at an oscillation wavelength of 98 nm.
A 165 nm film was formed so that the reflectance at the front end face was 2.5% at 0 nm. 4 × 10 ^-5 Tor during AlO _x film formation
average energy 150 eV, current density 20 in vacuum r
The plasma of 0 μA / cm ² was irradiated simultaneously with the supply of the raw material to the end face.

In order to further process the rear end face, the laser bar was once taken out of the vacuum chamber. To perform the same processing on the rear end face side as on the front end face side, 1 × 10 ⁻⁶ Torr using a 4.5 KW halogen lamp.
In a high vacuum for 3 minutes.
Amorphous Si was deposited on a 3 nm end face in a vacuum of × 10 ⁻⁷ Torr. Further, the SiO _x film is continuously formed to a thickness of 200 nm.
/ TiO _x 120 nm / SiO _x film 200 nm / Ti
The O _x a 120 nm / SiO _x film 200 nm / TiO _x to form a coating layer of 6-layer continuous with 120 nm,
A rear end face having a reflectance of 88% was produced. When forming the coating layer on the rear end face side, plasma irradiation was performed in the same manner as when forming the coating layer on the front end face side.

From the laser bar, 5 devices were mounted on a sub-mount for heat radiation, and packaged in a nitrogen atmosphere. As the average initial characteristics of the device, the threshold current was 23 mA at 25 ° C., and kink was observed at 350 mA and 250 mW. The oscillation wavelength of the device was 980 nm. FIG. 4 shows the results of a life test performed on this group. As a result of an acceleration test at 150 mW 70 ° C., 10
There was no sudden death at the time of 00hs, and a stable operation was confirmed.

When one sample of this laser bar was subjected to XPS measurement for end face analysis in the same manner as in Example 1, neither Ga-O nor As-O was detected.

Further, the band gap near the front end face of the active layer was measured by electron energy loss spectroscopy exactly in the same manner as in Example 1, and the band gap at the end face of the InGaAs active layer was 1.45 eV. . The energy gap between the quantum levels of the InGaAs quantum well active layer at room temperature determined from photoluminescence measurement was 1.29.
It was eV, and it was confirmed that the band gap near the end face was widened and the end face was transparent with respect to the oscillation wavelength due to the effect of the desorption of InAs mainly in the active layer. (Comparative Example 1)
Both the front end face and the rear end face do not form a Si passivation layer, and do not perform a step of selectively exposing the end face to a high temperature for making the end face transparent prior thereto, and form the coating layer by the IAD method. In the same manner as in Example 1 except that the ordinary electron beam evaporation method was used, the average initial characteristics of the device were as follows: the threshold current was 21 mA at 25 ° C., and kink was observed at 350 mA and 250 mW. Was.
This was the same result as in Example 1. However, the life test (150 m
W 70 ° C), all devices died suddenly after 150 hs. FIG. 5 shows the results.

When one sample of the laser bar was subjected to XPS measurement for the end face analysis in the same manner as in Example 1, both Ga—O and As—O were detected. When the band gap near the front end face of the active layer was measured by using electron energy loss spectroscopy in the same manner as in Example 1, the quantum gap between the quantum levels of the InGaAs quantum well active layer at room temperature obtained from photoluminescence measurement was measured. Energy gap was almost the same. (Comparative Example 2) The same as in Example 1 except that the Si passivation layer was not formed on both the front end face and the rear end face, and that the coating layer was formed using a normal electron beam evaporation method instead of the IAD method. In exactly the same way, the average initial characteristics of the device were that the threshold current was 21 mA at 25 ° C.
A kink was observed at 250 mA, mA. This was the same result as in Example 1. However, in a life test performed on a group of 10 devices, (150 mW 70
° C), four devices were confirmed to die suddenly after 1000 hs. FIG. 6 shows the results. In addition, the deterioration rate was higher than that of the first embodiment.

When one sample of the laser bar was subjected to XPS measurement in the same manner as in Example 1 for end face analysis, As-O was not detected. (Comparative Example 3) Before the formation of the Si passivation layer, neither the step of selectively exposing the end face to a high temperature for making the end face transparent nor the step of irradiating an electron beam were performed on both the front end face and the rear end face. Except for the above, the device was completely the same as that of the first embodiment. The average initial characteristics of the device were that the threshold current was 21 m at 25 ° C.
A, and kink was observed at 350 mA and 250 mW. This was the same result as in Example 1. However, in a life test (150 mW, 70 ° C.) performed on a group of 10 devices in the same number as in Example 1, all devices died suddenly after 400 hs. FIG. 7 shows the results.

When one sample of the laser bar was subjected to XPS measurement in the same manner as in Example 1 for end face analysis, both Ga—O and As—O were detected. When the band gap near the front end face of the active layer was measured by using electron energy loss spectroscopy in the same manner as in Example 1, the quantum gap between the quantum levels of the InGaAs quantum well active layer at room temperature obtained from photoluminescence measurement was measured. Energy gap was almost the same. (Comparative Example 4) Forming a coating layer without forming a Si passivation layer on both the front end face and the rear end face, and selectively exposing the end face to a high temperature for making the end face transparent prior thereto. Was performed in exactly the same manner as in Example 2 except that a normal electron beam evaporation method was used instead of the IAD method.
InGaAs measured by electron energy loss spectroscopy
The band gap of the quantum well active layer is 1.28 eV and PL
The value was almost the same as the value of the bulk region measured in. Also,
Life test (150 mW7
(0 ° C.), all devices died suddenly after 250 hs. FIG. 8 shows the results.

When one sample of the laser bar was subjected to XPS measurement in the same manner as in Example 1 for end face analysis, both Ga—O and As—O were detected. When the band gap near the front end face of the active layer was measured by using electron energy loss spectroscopy in the same manner as in Example 1, the quantum gap between the quantum levels of the InGaAs quantum well active layer at room temperature obtained from photoluminescence measurement was measured. Energy gap was almost the same.

[0069]

According to the present invention, light absorption at the end face of a semiconductor laser is stably suppressed for a long period of time by employing a window structure, and a passivation layer is formed of a coating made of a dielectric or a combination of a dielectric and a semiconductor. By inserting between these layers, a long-term stable end face can be realized, and a semiconductor laser that operates stably even when diffusion of the passivation layer occurs can be realized by a simple method. Yes, providing significant industrial benefits.

[Brief description of the drawings]

FIG. 1 is a perspective view of a semiconductor light emitting device of the present invention.

FIG. 2 is an explanatory cross-sectional view of the semiconductor laser according to the first embodiment of the present invention as viewed from the direction of the resonator.

FIG. 3 shows a life test result of the semiconductor laser according to the first embodiment of the present invention.

FIG. 4 is a result of a life test of the semiconductor laser of Example 2 of the present invention.

FIG. 5 is a life test result of the semiconductor laser of Comparative Example 1.

6 is a result of a life test of the semiconductor laser of Comparative Example 2. FIG.

FIG. 7 is a life test result of the semiconductor laser of Comparative Example 3.

8 is a result of a life test of the semiconductor laser of Comparative Example 4. FIG.

[Explanation of symbols]

1: substrate 2: buffer layer 3: first conductivity type cladding layer 4: active layer 5: second conductivity type first cladding layer 6: second etching stop layer 7: first etching stop layer 8: second conductivity type Nicladding layer 9: Current blocking layer
10: Cap layer 11: Contact layer 12: Electrode
13: electrode 14: passivation layer 15: coating layer 16: coating layer

Claims (21)

[Claims] 1. A method for manufacturing a semiconductor light emitting device having a resonator structure, comprising: forming a compound semiconductor layer including a first conductivity type cladding layer, an active layer, and a second conductivity type cladding layer on a substrate; A compound semiconductor layer is sequentially crystal-grown thereon, a cavity facet is formed by cleavage, and at least a part of constituent elements exposed on at least one facet and at least near the facet of the active layer is desorbed. Forming a passivation layer in the semiconductor light emitting device. 2. As means for desorbing a part of constituent elements near the end face of the active layer, at least one end face has
2. The method for manufacturing a semiconductor light emitting device according to claim 1, wherein light including a wavelength shorter than an oscillation wavelength determined by an electron beam, a heat ray, and / or an active layer is irradiated. 3. The active layer according to claim 1, wherein an area near the end face of the active layer, in which a part of the constituent element is desorbed, is transparent to the oscillation wavelength of the active layer. The manufacturing method of the semiconductor light emitting device according to the above. 4. The method according to claim 1, wherein the active layer contains In. 5. The method according to claim 1, wherein the active layer is formed of In _x Ga _{1 -x} As (0 <x
<1) or (Al _x Ga _{1 -x} ) _y In _{1 -y} P (0 <x, y <
5. The method for manufacturing a semiconductor light emitting device according to claim 4, wherein 1) is included. 6. The method for manufacturing a semiconductor light emitting device according to claim 1, wherein said active layer has a quantum well structure. 7. The method according to claim 1, wherein the cleavage is performed at normal pressure. 8. The method according to claim 7, wherein the cleavage is performed in the air or in a nitrogen atmosphere. 9. The semiconductor light emitting device according to claim 1, wherein the passivation layer is made of a material that becomes an n-type impurity when diffused into the active layer. Production method. 10. The method for manufacturing a semiconductor light emitting device according to claim 1, wherein said passivation layer contains Si. 11. The passivation layer having a thickness T _p (n
The method for manufacturing a semiconductor light emitting device according to any one of claims 1 to 10, wherein m) is formed so as to fall within a range represented by the following formula (I). 0.2 (nm) <T _p (nm) <λ / 8n (nm) (I) (where, in the formula (I), λ is the oscillation wavelength of the semiconductor light emitting element, and n is (It represents the real part of the refractive index at the wavelength λ (nm) of the activation layer.) 12. The method according to claim 1, further comprising, after forming the passivation layer, further forming a coating layer comprising a dielectric or a combination of a dielectric and a semiconductor on the surface thereof.
The method for manufacturing a semiconductor light emitting device according to any one of the above. 13. The method according to claim 12, wherein the coating layer is formed in a vacuum after forming the passivation layer. 14. The method for manufacturing a semiconductor light emitting device according to claim 12, wherein, when forming the coating layer, the supply of the coating layer material to the end face and the plasma irradiation are simultaneously performed in a vacuum. 15. The method according to claim 14, wherein the plasma irradiation is plasma irradiation of a Group 18 element. 16. The method according to claim 15, wherein the group 18 element is Ar. 17. The method for manufacturing a semiconductor light emitting device according to claim 16, wherein the energy of the irradiated Ar plasma is not less than 25 eV and not more than 300 eV. 18. The method according to claim 18, wherein the coating layer is made of AlO _x , T
iO _x, SiO _x, a method of manufacturing a semiconductor light emitting device according to any one of claims 12 to 17, characterized in that it consists of one or more combinations selected from the group consisting of SiN, Si and ZnS. 19. The method according to claim 12, wherein the coating layer includes a low reflection coating layer and a high reflection coating layer. 20. The low reflection coating layer is made of AlO _x
Wherein the highly reflective coating layer comprises AlO _x and Si
20. The method for manufacturing a semiconductor light emitting device according to claim 19, comprising: 21. The resonator according to claim 1, wherein the end face of the resonator is a (110) plane or a plane crystallographically equivalent thereto.
20. The method for manufacturing a semiconductor light emitting device according to any one of 20.