JP2002043692A - Semiconductor laser and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a semiconductor laser using a nitride-based III-V compound semiconductor and its manufacturing method by which high outputting can be realized. SOLUTION: A p-side contact layer 43 is provided corresponding to other areas excluding both ends of an active layer 30 in the direction A of a resonator. In addition, an insulation layer or a high resistance layer is provided between the p-side contact layer 43 and a p-side electrode 52, corresponding to other areas excluding both ends of the active layer 30 in the direction A of the resonator. Thus, both ends of the resonator 30 in the direction A of the resonator are non-injection areas of current, which correspond to the p-side contact layer 43 in the other areas excluding both ends of the active layer 30 in the direction A of the resonator. Therefore, non-light emission re-combination can be effectively prevented on the end faces 1a and 1b of the resonator and in their adjacent areas, thereby suppressing an increase in temperature on the end faces 1a and 1b thereof and in their adjacent areas and preventing COD.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a semiconductor laser using a nitride-based III-V compound semiconductor containing at least one of group 3B elements and at least nitrogen (N) of group 5B elements. .

[0002]

2. Description of the Related Art In recent years, in optical disk devices and magneto-optical disk devices, there has been an increasing demand for higher density or higher resolution of recording and reproduction.
2. Description of the Related Art Research and development of a semiconductor laser (laser diode; LD) capable of emitting light in a short wavelength range from a blue wavelength band to an ultraviolet region has been actively performed. Materials suitable for forming a semiconductor laser capable of emitting light in such a short wavelength range include GaN, A
A nitride III-V compound semiconductor represented by an lGaN mixed crystal or a GaInN mixed crystal is known. In order to realize recording / reproducing of a rewritable disk by a semiconductor laser using the nitride III-V compound semiconductor, a large optical output of at least about 30 mW is required.

[0003]

However, in this type of semiconductor laser, optical damage (Catastrophic Optical D / A) is caused near a pair of end faces facing each other in the cavity direction.
amage (COD), and it is difficult to increase the output. In this COD, non-radiative recombination of electrons and holes occurs more in the vicinity of the end face where a high-density interface order exists than in the inside, the carrier density decreases, light is absorbed near the end face, and the temperature decreases. As the temperature rises, it is known that this occurs due to a series of phenomena such as a decrease in the band gap, light absorption, and a further rise in temperature.

As one of means for solving the above-mentioned problem, a gallium nitride based semiconductor laser device in which the length of the ohmic electrode for supplying current to the active layer in the resonator direction is shorter than the length of the resonator has been proposed. (Japanese Patent Laid-Open No. 11-
No. 340573). However, this semiconductor laser device has a problem that the manufacturing process is complicated.

The present invention has been made in view of such a problem, and an object of the present invention is to provide a semiconductor laser using a nitride-based III-V compound semiconductor which can easily achieve high output. is there.

[0006]

A semiconductor laser according to the present invention is composed of a nitride III-V compound semiconductor containing at least one of the group 3B elements and at least nitrogen of the group 5B element. Semiconductor laser in which an n-type semiconductor layer, an active layer, and a p-type semiconductor layer are sequentially stacked, an n-side electrode is in ohmic contact with the n-type semiconductor layer, and an p-side electrode is in ohmic contact with the p-type semiconductor layer Wherein the p-type semiconductor layer corresponds to a region other than at least one end of the active layer in the resonator direction.
A p-side contact layer in ohmic contact with the side electrode,
At least one end of the active layer in the resonator direction is a current non-injection region.

Another semiconductor laser according to the present invention is an n-type nitride-based III-V compound semiconductor containing at least one of the group 3B elements and at least nitrogen (N) of the group 5B element. Semiconductor layer, active layer and p
A semiconductor laser in which an n-type semiconductor layer is sequentially stacked, an n-side electrode is in ohmic contact with the n-type semiconductor layer, and a p-side electrode is in ohmic contact with the p-type semiconductor layer. Has a p-side contact layer that makes ohmic contact with the p-side electrode, and an insulating layer or a high-resistance layer is provided between at least one end in the resonator direction between the p-side contact layer and the p-side electrode. Preferably, at least one end of the active layer in the resonator direction is a current non-injection region.

[0008] Still another semiconductor laser according to the present invention is:
An n-type semiconductor layer, an active layer, and a p-type semiconductor layer each formed of a nitride III-V compound semiconductor containing at least one of the group 3B elements and at least nitrogen of the group 5B element.
A semiconductor laser in which an n-type semiconductor layer is sequentially stacked, an n-side electrode is in ohmic contact with the n-type semiconductor layer, and a p-side electrode is in ohmic contact with the p-type semiconductor layer. Is provided with an insulating film having an opening corresponding to the other region except at least one end of the active layer in the direction of the resonator, and the p-side electrode is connected to the p-type semiconductor layer through the opening of the insulating film with the ohmic contact. The active layer is in contact with at least one end of the active layer in the resonator direction, which is a current non-injection region.

A method for manufacturing a semiconductor laser according to the present invention comprises:
An n-type semiconductor layer, an active layer, and a p-type semiconductor layer each composed of a nitride-based III-V compound semiconductor containing at least one of the group 3B elements and at least nitrogen (N) of the group 5B element are sequentially formed. A method of manufacturing a semiconductor laser in which an n-side electrode is in ohmic contact with an n-type semiconductor layer and a p-side electrode is in ohmic contact with a p-type semiconductor layer. Forming a p-side contact layer in ohmic contact with the p-side electrode as a portion, and forming at least a part of at least one end of the p-side contact layer in the resonator direction on the p-side electrode side into an insulating layer or a high And a step of forming a resistance layer.

In the semiconductor laser according to the present invention, the p-side contact layer is provided corresponding to another region except at least one end of the active layer in the resonator direction, or the p-side contact layer and the p-side electrode are provided. An insulating layer or a high-resistance layer is provided at at least one end in the resonator direction between them, or an opening is formed corresponding to another region excluding at least one end of the active layer in the resonator direction. By providing the insulating film having at least one end of the active layer in the cavity direction in the resonator direction is a current non-injection region, so that a temperature rise during operation of the end in the current non-injection region is suppressed. You. Therefore, there is no possibility that this end is broken, and high output can be achieved.

In the method of manufacturing a semiconductor laser according to the present invention, after the p-side contact layer is formed, at least one end of the p-side contact layer in the direction of the cavity is formed.
At least a part of the side electrode is an insulating layer or a high resistance layer.

[0012]

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

FIG. 1 shows a configuration of a semiconductor laser 1 according to a first embodiment of the present invention. This semiconductor laser 1 is provided on one surface side of a substrate 11.
An n-type semiconductor layer 20, an active layer 30, and a p-type semiconductor layer 40 are sequentially stacked from the substrate 11 side. Substrate 11
Is, for example, sapphire (α-Al) having a thickness in the stacking direction (hereinafter simply referred to as a thickness) of about 80 μm.
₂ O ₃ ), and the n-type semiconductor layer 20, the active layer 30, the p-type semiconductor layer 40, and the like are formed on the c-plane of the substrate 11. The n-type semiconductor layer 20, the active layer 30, and the p-type semiconductor layer 40 are 3B in the short-periodic periodic table.
It is made of a nitride III-V compound semiconductor containing at least one of the group III elements and at least nitrogen of the group 5B element in the short period periodic table.

The n-type semiconductor layer 20 has, for example, an n-side contact layer 21, an n-type cladding layer 22, and an n-type guide layer 23 which are sequentially stacked from the substrate 11 side. The n-side contact layer 21 has a thickness of, for example, 3 μm,
It is composed of n-type GaN to which silicon (Si) is added as a type impurity. The n-type cladding layer 22 is, for example,
It has a thickness of 1 μm and is made of an n-type AlGaN mixed crystal to which silicon is added as an n-type impurity. The n-type guide layer 23 has a thickness of, for example, 0.1 μm, and is made of n-type GaN to which silicon is added as an n-type impurity.

The active layer 30 has, for example, a thickness of 30 nm and Ga _x In ₁ -xN of different composition (where x ≧ 0).
It has a multiple quantum well structure in which mixed crystal layers are stacked.

The p-type semiconductor layer 40 includes, for example, the active layer 30
, A p-type guide layer 41, a p-type cladding layer 42, and a p-side contact layer 43 laminated in this order. p
The mold guide layer 41 has a thickness of, for example, 0.1 μm,
It is made of p-type GaN to which magnesium (Mg) is added as a p-type impurity. The p-type cladding layer 42
For example, it has a thickness of 0.8 μm and is made of a p-type AlGaN mixed crystal to which magnesium is added as a p-type impurity. The p-side contact layer 43 has, for example, a thickness of 0.5 μm and is made of p-type GaN to which magnesium is added as a p-type impurity. Note that a part of the p-type cladding layer 42 and the p-side contact layer 43 are formed in a narrow band shape extending in the resonator direction A, and perform current confinement.

The p-side contact layer 43 is provided corresponding to at least one end of the active layer 30 in the resonator direction A, for example, a region other than both ends. As a result, at least one end of the active layer 30 in the resonator direction A is a current non-injection region, and the current injection region functioning as a light emitting unit is other than at least one end in the resonator direction A. The region corresponds to the p-side contact layer 43. Here, the current non-injection region does not mean a region in which no current flows at all, but a region in which no current is actively injected. The width of the current non-injection region in the resonator direction A is 1
It is preferable that the thickness be within 00 μm. If it is larger than that, the contact portion between the p-side contact layer 43 and a p-side electrode 52 to be described later is reduced, so that the drive voltage is increased and a current is uniformly supplied from the p-side electrode 52 to the p-side contact layer 43 This is because the threshold current increases without being injected.
The width of the current non-injection region in the resonator direction A is 1
More preferably, it is within the range of 0 μm to 50 μm. This is because the operating characteristics of the semiconductor laser 1 are more stable within this range.

In the semiconductor laser 1, the n-side contact layer 21 in a direction perpendicular to the cavity direction 1 is provided.
Of the other n-type cladding layer 22, n-type guide layer 23,
The active layer 30 is wider than the p-type semiconductor layer 40, and the n-type cladding layer 2
2, an n-type guide layer 23, an active layer 30, and a p-type semiconductor layer 40 are stacked.

On the surface of the n-side contact layer 21 and the surface of the p-type semiconductor layer 40, for example, silicon dioxide (Si)
An insulating film 12 of O ₂ ) is formed. The insulating film 12 is provided with openings corresponding to the n-side contact layer 21 and the p-side contact layer 43, respectively. The openings corresponding to these openings are provided on the n-side contact layer 21 and the p-side contact layer 43. Thus, an n-side electrode 51 and a p-side electrode 52 are formed. The n-side electrode 51 has a structure in which, for example, titanium (Ti) and aluminum (Al) are sequentially laminated and alloyed by heat treatment.
Ohmic contact with the side contact layer 21. The p-side electrode 52 has a structure in which, for example, palladium (Pd), platinum (Pt), and gold (Au) are sequentially stacked.
Ohmic contact with the side contact layer 43. In addition,
The entire surface of the p-side contact layer 43 is exposed through the opening of the insulating film 12 and is in ohmic contact with the entire surface of the p-side electrode 52.

In the semiconductor laser 1, a pair of side faces facing the active layer 30 in the resonator direction A are resonator end faces 1a and 1b, and the pair of resonator end faces 1a and 1b have A pair of reflecting mirror films (not shown) are formed. The reflectance is adjusted so that one of the pair of reflecting mirror films has a low reflectance and the other has a high reflectance. Thereby, the active layer 30
Is amplified by reciprocating between a pair of reflecting mirror films, and is emitted as a laser beam from the reflecting mirror film having a low reflectance. The p-side contact layer 43
Is provided corresponding to the other region except one end of the active layer 30 in the resonator direction A. When only one end is used as the current non-injection region, the current non-injection region It is preferable that the end portion is formed as a reflecting mirror film having a low reflectance.

Semiconductor laser 1 having such a configuration
Can be manufactured as follows. Here, a case where a plurality of semiconductor lasers 1 are manufactured will be described as an example.

FIGS. 2 and 3 show the manufacturing process for one semiconductor laser forming region. In addition,
2 (A), 2 (B) and 3 (A) show cross-sectional structures perpendicular to the resonator direction A. FIG. 3 (B) shows the p-side contact layer 43 along the resonator direction A. It shows a cross-sectional structure cut so as to include. First, for example, a substrate 11 having a plurality of semiconductor laser forming regions and made of sapphire having a thickness of about 400 μm is prepared. Next, as shown in FIG. 2A, an n-type GaN layer is formed on the c-plane of the substrate 11 by, for example, the MOCVD method.
Side contact layer 21, n-type clad layer 22 made of n-type AlGaN mixed crystal, n-type guide layer 2 made of n-type GaN
3, an active layer 30 of GaInN mixed crystal, a p-type guide layer 41 of p-type GaN, a p-type cladding layer 42 of p-type AlGaN mixed crystal, and a p-side contact layer 43 of p-type GaN are sequentially grown.

When MOCVD is performed, the source gas of gallium is, for example, trimethylgallium ((CH ₃ )).
₃ Ga), the raw material as a gas, for example trimethyl aluminum aluminum _{((CH 3) 3 Al)} , indium as the raw material gas such as trimethyl indium ((C
As the source gas for H ₃ ) ₃ In) and nitrogen, for example, ammonia (NH ₃ ) is used. For example, monosilane (SiH ₄ ) is used as a silicon source gas, and bis = cyclopentadienyl magnesium ((C ₅ H ₅ ) ₂ Mg) is used as a magnesium source gas.

After growing the p-side contact layer 43,
For example, a stripe-shaped mask (not shown) made of silicon dioxide is formed on the p-side contact layer 43 by using an evaporation method. Subsequently, as shown in FIG. 2B, a part of the p-side contact layer 43 and a part of the p-type cladding layer 42 are selectively etched by RIE (Reactive Ion Etching) or the like using this mask, and The upper part of the mold cladding layer 42 and the p-side contact layer 43 are formed in a narrow band shape. After that, the mask is removed.

Next, a mask (not shown) made of silicon dioxide is selectively formed on the p-side contact layer 43 and the p-type cladding layer 42 by using, for example, an evaporation method. Subsequently, as shown in FIG. 3A, the p-type cladding layer 42, the p-type guide layer 41, and the active layer 3 are formed using this mask.
The 0, n-type guide layer 23, the n-type cladding layer 22, and a part of the n-side contact layer 21 are sequentially etched by RIE or the like to expose the n-side contact layer 21 on the surface. After that, the mask is removed.

After removing the mask, a mask (not shown) made of silicon dioxide is formed on the entire surface by, for example, a vapor deposition method. Subsequently, using a photolithography technique, openings are formed in a mask (not shown) corresponding to the division plane of the semiconductor laser formation region in the direction perpendicular to the cavity direction A.
Next, as shown in FIG. 3B, for example, RIE is performed using the mask in which the opening is formed, and the p-side contact layer 43 is formed in at least one of the semiconductor laser forming regions in the direction perpendicular to the resonator direction A. , For example, both ends are removed. After that, the mask is removed.

After removing the mask, an insulating film 12 made of silicon dioxide is formed on the entire surface by, for example, a vapor deposition method.
Subsequently, a not-shown resist film is formed on the entire surface, and a not-shown resist pattern having an opening corresponding to the formation position of the n-side electrode 51 is formed. Thereafter, etching is performed using this resist pattern as a mask, and the insulating film 12 is selectively removed to form an opening in the insulating film 12. Next, for example, titanium and aluminum are sequentially deposited on the entire surface (that is, on the n-side contact layer 21 from which the insulating film 12 is selectively removed and the resist film (not shown)),
The n-side electrode 51 is formed by removing (lifting off) the resist film (not shown) together with each metal deposited thereon.
Subsequently, a heat treatment is performed to alloy the n-side electrode 51.

After the heat treatment, a resist film (not shown) is formed on the entire surface, and a resist pattern (not shown) having an opening corresponding to the p-side contact layer 43 is formed.
Thereafter, etching is performed using this resist pattern as a mask, and the insulating film 12 is selectively removed.
An opening is formed in the opening. Subsequently, the entire surface (that is, the insulating film 1)
2. Exposed surface of p-type cladding layer 42, p-side contact layer 4
A resist film (not shown) is formed on the third and n-side electrodes 51), and a resist pattern (not shown) having an opening corresponding to the formation position of the p-side electrode 52 is formed. after that,
On the entire surface (that is, on the exposed surface of the p-type cladding layer 42, the p-side contact layer 43, and the resist film not shown),
For example, palladium, platinum, and gold are sequentially deposited, and a resist film (not shown) is removed (lifted off) together with each metal deposited thereon. Thus, the p-side electrode 52 is formed.

After the formation of the p-side electrode 52, the substrate 11 is ground to a thickness of, for example, about 80 μm. Next, division is performed vertically between the adjacent p-side contact layers 43 with respect to the resonator direction A. Thereby, resonator end faces 1a and 1b are formed. After that, the resonator end faces 1a,
1b, a not-shown reflecting mirror film is formed. Furthermore,
Resonator direction A corresponding to the formation region of each semiconductor laser 1
And split in parallel. Thereby, a plurality of semiconductor lasers 1 shown in FIG. 1 are completed.

The semiconductor laser 1 operates as follows.

In this semiconductor laser 1, when a predetermined voltage is applied between the n-side electrode 51 and the p-side electrode 52, a current is injected into the active layer 30 and light emission occurs due to electron-hole recombination. . This light is reflected by a reflecting mirror film (not shown), reciprocates between them, causes laser oscillation, and is emitted to the outside as a laser beam. Here, the p-side contact layer 4
3 is provided corresponding to the other region except at least one end of the active layer 30 in the resonator direction A,
At least one end of the active layer 30 in the resonator direction A is a current non-injection region. Therefore, non-radiative recombination in at least one of the resonator end faces and the vicinity thereof is effectively prevented. Therefore, a rise in the temperature of the resonator end face and the vicinity thereof is suppressed, and COD is prevented.

As described above, according to the semiconductor laser 1 of the present embodiment, the p-side contact layer 43 in ohmic contact with the p-side electrode 52 is formed by removing at least one end of the active layer 30 in the resonator direction A. Provided corresponding to the area of
Since at least one end of the active layer 30 in the resonator direction A is a current non-injection region, non-radiative recombination of electrons and holes in the end face of the resonator and in the vicinity thereof is easily prevented. can do. Therefore, it is possible to suppress a rise in the temperature of the resonator end faces 1a, 1b and the vicinity thereof, and it is possible to prevent the occurrence of COD in the resonator end faces 1a, 1b and the vicinity thereof. Therefore, it is possible to easily increase the output.

In particular, if the reflectivity of the reflecting mirror film formed on the end side which is the current non-injection region is made low, the temperature rise in the cavity end face from which the laser beam is emitted and in the vicinity thereof can be reduced. This is more effective because COD can be suppressed and COD can be prevented from being generated in the cavity end face and its vicinity.

FIG. 1 shows a case where the p-side electrode 52 is also provided in regions corresponding to both ends of the active layer 30 in the resonator direction A. However, as shown in FIG. Similarly to the contact layer 43, the p-side electrode 52A may be provided in a region other than both ends of the active layer 30 in the resonator direction A. In that case, the shape of the resist pattern formed when forming the p-side electrode 52A may be changed. As described above, when the p-side electrode 52A as well as the p-side contact layer 43 are provided so as to correspond to regions other than both ends of the active layer 30 in the resonator direction A, the p-side electrode 62 hangs down during manufacturing. A short circuit caused by contact with the n-type semiconductor layer 20 can be prevented.

[Second Embodiment] FIG. 5 shows the configuration of a semiconductor laser 2 according to a second embodiment of the present invention. This semiconductor laser 2 has a high resistance layer 64 corresponding to the p-side contact layer 43 at at least one end, for example, both ends, in the resonator direction A, except that
Others have the same configuration, operation and effect as the first embodiment. Therefore, here, the same components are denoted by the same reference numerals, and detailed description thereof will be omitted.

The high-resistance layer 64 is, for example, a layer in which the p-type semiconductor layer is damaged by an external impact or the like and has a high resistance. Therefore, also in the present embodiment, both ends of the active layer 30 in the resonator direction A are current non-injection regions.

In the semiconductor laser 2, for example, after a p-side contact layer 43 is grown on the p-type cladding layer 42, at least the p-side contact layer 43 in the resonator direction A is etched by an etching method such as RIE. It can be manufactured in the same manner as in the first embodiment, except that one end, for example, both ends are selectively damaged and the high resistance layer 64 is formed. In addition, instead of etching, damage may be caused by irradiating oxygen, ozone, or plasma to form the high-resistance layer 64. In this case, however, a part of the p-side contact layer 43 on the p-side electrode side is not cut off as shown in FIG. 5, and even if it is cut off, it is very small. According to these manufacturing methods, the high resistance layer 64 can be easily formed, and at least one end of the active layer 30 in the resonator direction can be easily set as the current non-injection region.
In particular, high-resistance layers can be formed more easily by RIE or irradiation with oxygen, ozone, or plasma.

In the present embodiment, the p-side contact layer 43 is formed in a region other than at least one end of the active layer 30 in the resonator direction A. As shown in FIG.
3, the high-resistance layer 64 is provided between the p-side contact layer 43 and the p-side electrode 52 at at least one end in the resonator direction A. Is also good.

[Third Embodiment] FIG. 7 shows a configuration of a semiconductor laser 3 according to a third embodiment of the present invention. FIG. 7 shows a cross-sectional structure cut so as to include the p-side contact layer 43 in the resonator direction A. This semiconductor laser 3 is the same as the first embodiment except that an insulating layer 74 is provided corresponding to the p-side contact layer 43 at at least one end, for example, both ends, in the resonator direction A. It has a similar configuration, operation and effect. Therefore, here, the same components are denoted by the same reference numerals, and detailed description thereof will be omitted.

The insulating layer 74 is made of, for example, an element capable of increasing the resistance, such as oxygen, aluminum or boron, or a nitride III-V compound semiconductor doped with an n-type impurity such as silicon. I have. Therefore, also in the present embodiment, both ends of the active layer 30 in the resonator direction A are current non-injection regions.

The semiconductor laser 3 is formed, for example, by growing a p-side contact layer 43 on a p-type cladding layer 42 and then irradiating oxygen or ozone in a radical state, or by ion implantation or impurity diffusion. For example, an insulating layer 74 is formed by selectively adding an element capable of increasing resistance or an n-type impurity to at least one end, for example, both ends of the p-side contact layer 43 in the resonator direction A. Except for this, it can be manufactured in the same manner as in the first embodiment. According to these manufacturing methods, the insulating layer 74 can be easily formed, and at least one end of the active layer 30 in the resonator direction can easily be a current non-injection region. Above all, irradiation with oxygen or ozone makes it easier to form the insulating layer.

In this embodiment, the p-side contact layer 43 is formed so as to correspond to the other region except at least one end of the active layer 30 in the resonator direction A. As shown in FIG.
3, an element capable of increasing the resistance or an n-type impurity is selectively added to a part of the p-side electrode 52 side, and the p-side contact layer 43 and the p-side contact layer 43 at least at one end in the resonator direction A are added. You may make it provide the insulating layer 74 between the side electrodes 52.

[Fourth Embodiment] FIG. 9 shows the configuration of a semiconductor laser 4 according to a fourth embodiment of the present invention. The semiconductor laser 4 includes a p-side contact layer 83 and an insulating film 92 having different shapes from the p-side contact layer 43 and the insulating film 12 of the semiconductor laser 1 according to the first embodiment, respectively. Except for the above, the other configuration is the same as that of the semiconductor laser 1. Therefore,
Here, the same components are denoted by the same reference numerals, and detailed description thereof will be omitted.

The p-side contact layer 83 extends in the resonator direction A, and is also provided in at least one end of the active layer 30 in the resonator direction A, for example, a region corresponding to both ends. The insulating film 92 is provided adjacent to the p-side semiconductor layer 80 and the n-side contact layer 21, and has an opening 92 a corresponding to another region except at least one end of the active layer 30 in the resonator direction A. have. Thus, the ohmic contact between the p-side contact layer 83 and the p-side electrode 52 is limited to a region other than at least one end of the active layer 30 in the resonator direction A.
Therefore, also in the present embodiment, at least one end of the active layer 30 in the resonator direction A is a current non-injection region. The width of the current non-injection region in the resonator direction A is preferably within 100 μm, more preferably 10 μm to 5 μm, as in the first embodiment.
It is within the range of 0 μm. Note that, similarly to the first embodiment, an opening corresponding to the n-side contact layer 21 is also provided in the insulating film 92.

The semiconductor laser 4 having such a configuration
Can be manufactured as follows.

First, similarly to the first embodiment, the n-type semiconductor layer 20 and the active layer 30
Then, the p-type semiconductor layer 80 is sequentially grown, and after the upper part of the p-type cladding layer 42 and the p-side contact layer 73 are formed into a narrow band shape, the n-side contact layer 21 is exposed on the surface.
Next, after an insulating film 92 made of silicon dioxide is formed on the entire surface by, for example, a vapor deposition method, the n-side electrode 51 is formed in the same manner as in the first embodiment.

Subsequently, an opening 92a is formed in the insulating film 92 so as to correspond to at least one end portion of the active layer 30 in the resonator direction A, for example, a region other than both end portions. After that, the p-side electrode 52 is formed in the same manner as in the first embodiment. The subsequent steps are the same as in the first embodiment.

The semiconductor laser 4 operates similarly to the semiconductor laser 1 according to the first embodiment.

As described above, according to the semiconductor laser 4 according to the present embodiment, the insulating film 92 having the opening 92a corresponding to the other region except the both ends of the active layer 30 in the resonator direction A is formed by the p-type semiconductor. The p-side electrode 5 is disposed adjacent to the layer 80.
2 and the p-side contact layer 83 are connected to the opening 92a of the insulating film 92.
, And at least one end of the active layer 30 in the resonator direction A is defined as a current non-injection region. Non-radiative recombination with holes can be easily prevented.

As described above, the present invention has been described with reference to the embodiments. However, the present invention is not limited to the above embodiments and can be variously modified. For example, in the first embodiment, only the p-side contact layer 43 is provided corresponding to the other region except at least one end of the active layer 30 in the resonator direction A. Layer 43
In addition, at least a part of the p-type cladding layer 42 may be provided corresponding to another region except at least one end of the active layer 30 in the resonator direction A. Also in this case, the effects of the present invention can be obtained without deteriorating the characteristics of the semiconductor laser 1. Similarly, in the second embodiment, only the p-side contact layer 43 is damaged, and in the third embodiment, an element or n-type element capable of increasing the resistance only in the p-side contact layer 43 is used. Although the impurities are added, at least a part of the p-type cladding layer 42 may be damaged in addition to the p-side contact layer 43, or they may be added.

In the above embodiment, the n-side contact layer 21, the n-type cladding layer 22, the n-type guide layer 23, the active layer 30, the p-type guide layer 41, the p-type clad layer 42, and the p-side contact layer 43 , 83 have been described with specific examples, but each of these layers is made of another group III-V nitride semiconductor containing at least one of the group 3B elements and nitrogen. You may do so.

Further, in the above embodiment, the n-side contact layer 21, the n-type cladding layer 22, the n-type guide layer 23, the active layer 30, the p-type guide layer 41, the p-type clad layer 42, and the p-side contact layer 43 , 83 are sequentially stacked, but the present invention can be similarly applied to a semiconductor laser having another structure. For example, the n-type guide layer 23 and the p-type guide layer 41 do not have to be provided, and a deterioration preventing layer may be provided between the active layer 30 and the p-type guide layer 41. Further, in the above embodiment, a part of the p-type cladding layer 42 and the p-side contact layers 43 and 8 are formed.
Although the current constriction is performed by forming the thin band 3 into a narrow band, the current confinement may be performed by another structure. Further, in the above embodiment, the ridge waveguide type semiconductor laser combining the gain waveguide type and the refractive index waveguide type has been described as an example. The same can be applied to a semiconductor laser of a type.

In the above embodiment, the substrate 11 is made of sapphire.
It may be made of another material such as silicon carbide (SiC), spinel (MgAl ₂ O ₄ ), or gallium arsenide (GaAs).

In addition, in the above embodiment, the n-type semiconductor layer 20, the active layer 30, and the p-type semiconductor layers 40, 60, 7
Although the case where 0 and 80 are formed by the MOCVD method has been described, they may be formed by other vapor phase growth methods such as the MBE method and the hydride vapor phase growth method. In addition,
The hydride vapor deposition method refers to a vapor deposition method in which halogen contributes to transport or reaction.

[0055]

As described above, according to the semiconductor laser of any one of the first to sixth aspects, the p-side contact layer is formed by removing at least one end of the active layer in the resonator direction. Or by providing an insulating layer or a high-resistance layer at at least one end in the resonator direction between the p-side contact layer and the p-side electrode, or in the resonator direction. Is provided with an insulating film having an opening corresponding to the other region except at least one end of the active layer, so that at least one end of the active layer in the resonator direction is a current non-injection region. Therefore, non-radiative recombination of electrons and holes at at least one end of the active layer in the resonator direction can be easily prevented. Accordingly, it is possible to suppress an increase in the temperature of at least one end of the active layer in the resonator direction, and it is possible to prevent the occurrence of COD at this end. Therefore, it is possible to easily increase the output.

According to the method of manufacturing a semiconductor laser according to the seventh or eighth aspect, at least a part of at least one end of the p-side contact layer in the resonator direction on the side of the p-side electrode is an insulating layer. Or because it is a high resistance layer,
There is an effect that the semiconductor laser of the present invention can be easily manufactured.

[Brief description of the drawings]

FIG. 1 is a partially cutaway perspective view illustrating a configuration of a semiconductor laser according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view illustrating a manufacturing process of the semiconductor laser illustrated in FIG.

FIG. 3 is a sectional view illustrating a manufacturing step following FIG. 2;

FIG. 4 is a perspective view illustrating a configuration of a semiconductor laser according to a modification of the semiconductor laser illustrated in FIG.

FIG. 5 is a partially cutaway perspective view illustrating a configuration of a semiconductor laser according to a second embodiment of the present invention.

FIG. 6 is a perspective view showing a configuration of a semiconductor laser according to a modification of the semiconductor laser shown in FIG.

FIG. 7 is a perspective view illustrating a configuration of a semiconductor laser according to a third embodiment of the present invention.

FIG. 8 is a perspective view showing a configuration of a semiconductor laser according to a modification of the semiconductor laser shown in FIG.

FIG. 9 is a perspective view illustrating a configuration of a semiconductor laser according to a fourth embodiment of the present invention, partially cut away;

[Explanation of symbols]

1, 2, 3, 4 ... semiconductor laser, 1a, 1b ... cavity facet, 11 ... substrate, 12, 92 ... insulating film, 20 ... n-type semiconductor layer, 21 ... n-side contact layer, 22 ... n-type clad layer , 23 ... n-type guide layer, 30 ... active layer, 40, 60,
70, 80 ... p-type semiconductor layer, 41 ... p-type guide layer, 42
... p-type cladding layer, 43, 83 ... p-side contact layer, 5
1: n-side electrode, 52, 52A: p-side electrode, 64: high resistance layer, 74: insulating layer, 92a: opening, A: resonator direction

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Tsuyoshi Tojo 3-53-3 Shiratori, Shiroishi City, Miyagi Prefecture Inside Sony Shiroishi Semiconductor Co., Ltd. 2 Inside Sony Shiroishi Semiconductor Co., Ltd. (72) Inventor Shiro Uchida 3-53-3 Shiratori, Shiroishi City, Miyagi Prefecture Inside Sony Corporation Shiroishi Semiconductor Co., Ltd. F term (reference) 5F073 AA11 AA13 AA45 AA51 AA74 AA83 AA87 CA07 CB05 DA05 DA29 DA35 EA28

Claims (8)

[Claims] 1. The method according to claim 1, wherein at least one of the group 3B elements and 5
An n-type semiconductor layer, an active layer, and a p-type semiconductor layer each composed of a nitride III-V compound semiconductor containing at least nitrogen (N) of the group B elements are sequentially laminated, and the n-type semiconductor layer is formed. A semiconductor laser in which an n-side electrode is in ohmic contact with, and a p-side electrode is in ohmic contact with the p-type semiconductor layer, wherein the p-type semiconductor layer has at least one of an active layer in a resonator direction. A p-side contact layer in ohmic contact with the p-side electrode corresponding to the other region except the end, and at least one end of the active layer in the resonator direction is a current non-injection region A semiconductor laser, comprising: 2. The semiconductor laser according to claim 1, wherein the width of the current non-injection region in the cavity direction is within 100 μm. 3. The method according to claim 1, wherein at least one of the group 3B elements and 5
An n-type semiconductor layer, an active layer, and a p-type semiconductor layer each composed of a nitride III-V compound semiconductor containing at least nitrogen (N) of the group B elements are sequentially laminated, and the n-type semiconductor layer is formed. A semiconductor laser in which an n-side electrode is in ohmic contact with, and a p-side electrode is in ohmic contact with the p-type semiconductor layer, wherein the p-type semiconductor layer has a p-side in ohmic contact with the p-side electrode. A contact layer, between the p-side contact layer and the p-side electrode, an insulating layer or a high resistance layer is provided at at least one end in the resonator direction, and the active layer in the resonator direction in the resonator direction; A semiconductor laser, wherein at least one end is a current non-injection region. 4. The semiconductor laser according to claim 3, wherein the width of the current non-injection region in the resonator direction is within 100 μm. 5. The method according to claim 1, wherein at least one of the group 3B elements and 5
An n-type semiconductor layer, an active layer, and a p-type semiconductor layer each composed of a nitride III-V compound semiconductor containing at least nitrogen (N) of the group B elements are sequentially laminated, and the n-type semiconductor layer is formed. A semiconductor laser in which an n-side electrode is in ohmic contact with, and a p-side electrode is in ohmic contact with the p-type semiconductor layer, wherein the p-type semiconductor layer has at least one of an active layer in a resonator direction. An insulating film having an opening corresponding to the other region except the end portion is provided, and the p-side electrode is in ohmic contact with the p-type semiconductor layer through the opening of the insulating film,
A semiconductor laser, wherein at least one end of the active layer in the resonator direction is a current non-injection region. 6. The semiconductor laser according to claim 5, wherein the width of the current non-injection region in the resonator direction is within 100 μm. 7. At least one of the group 3B elements and 5
An n-type semiconductor layer, an active layer, and a p-type semiconductor layer each composed of a nitride III-V compound semiconductor containing at least nitrogen (N) of the group B elements are sequentially laminated, and the n-type semiconductor layer is formed. A method of manufacturing a semiconductor laser in which an n-side electrode is in ohmic contact with the p-type semiconductor layer, and the p-side electrode is in ohmic contact with the p-type semiconductor layer. Forming a p-side contact layer, and forming at least a part of at least one end of the p-side contact layer in the resonator direction on the p-side electrode side as an insulating layer or a high-resistance layer. A method for manufacturing a semiconductor laser, comprising: 8. Irradiation of oxygen, ozone or plasma,
The method according to claim 7, wherein the insulating layer or the high-resistance layer is formed by etching, ion implantation, or impurity diffusion.