JPH07283483A - Manufacture of semiconductor laser element - Google Patents

Abstract

PURPOSE:To reduce the threshold current of a semiconductor laser element and moreover, to make it possible to obtain the high output of the element by a method wherein before a coating film is applied on the resonator end face of the semiconductor laser element, a hydrogen radical beam is emitted on the resonator end face. CONSTITUTION:A buffer layer 2, an optical waveguide layer 3, a multiple quantum well structure active layer 4 consisting of two layers of quantum well layers, one layer of a quantum barrier layer and optical separation confinement layers provided on both sides of the quantum well layers, an optical waveguide layer 5 and a buffer layer 6 are epitaxially grown on a substrate 1. After this, an SiO2 mask is formed and the layers 6 and 5 are removed by etching to form a ridge stripe. Then, a photoabsorption layer 7, which is also used in combination as a current constricting layer, is selectively grown as the SiO2 growth, a P side electrode 9 and an N side electrode 10 are deposited and the laminated material is cleaved to cut out in the form of bar-shaped element. After this, the sample of the bar-shaped element is set on an RF sputtering device, a hydrogen radical beam is emitted on a resonator end face and after an end face protective film is continuously formed, an element is scribed and is cut out.

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 high power semiconductor laser device suitable for an optical information terminal and a light source for optical application measurement or optical communication.

[0002]

2. Description of the Related Art In the prior art, for example, an end face non-excited structure is manufactured by providing a current confinement layer near the end face of the cavity of an AlGaInP semiconductor laser, and high output is achieved by suppressing the temperature rise near the end face. For example, Electronics Letters 1991, 27, 66
1 (Electron. Lett., 27, 661 (1991)).

[0003]

In the prior art, as an element structure of a semiconductor laser, an end face non-excited structure is formed as a shape in which a current confinement layer is provided in the vicinity of the end face of a resonator to achieve high output. However, no details have been given on the high output characteristics achieved by using the end face non-excited structure in which the current non-injection region is formed by performing the surface treatment on the end face and the fabrication technique thereof.

Even if the current non-injection region is formed by the conventional technique, the leakage current in the vicinity of the end face of the resonator becomes large due to the surrounding of the current curve. This leakage current causes a large temperature rise in the active layer near the end surface.
The forbidden band width is reduced and the optical waveguide loss is increased without forming a transparent region.

For this reason, there has been a problem that the threshold current of the element increases even if the end face current non-injection region is provided by the conventional technique. This becomes more noticeable at high temperatures. Furthermore, since a higher operating current is required at high output, the optical output tends to be saturated.

An object of the present invention is to fabricate an end face non-excited structure by a surface treatment technique for forming a current non-injection region in the vicinity of a cavity end face, which is different from the conventional technique, and reproducibility is not affected by a built-in shape. While ensuring good device characteristics,
It is an object of the present invention to provide a method for manufacturing a semiconductor laser device capable of reducing the threshold current and obtaining a higher output than ever before.

[0007]

[Means for Solving the Problems]
In the end face non-excited structure produced by providing the current confinement layer, the leakage current is large and incomplete, whereas in the present invention, a manufacturing method having a high process matching degree to the resonator end face is used. Provided is a semiconductor laser device having a more complete non-excitation structure.

According to the method used in the present invention, the end faces of the resonator of the semiconductor laser device are irradiated with a hydrogen radical beam in the same high vacuum apparatus before the coating film is formed. By this step, atomic hydrogen can be accurately diffused and adsorbed and fixed to the semiconductor end face and the vicinity thereof. Atomic hydrogen reduces oxygen at the cavity facets and desorbs it from the surface, and adsorbs to dangling bonds of surface atoms to prevent activation against oxidation. As a result, the deep level peculiar to the surface atoms can be removed, and the forbidden band width originally possessed by the semiconductor is exhibited. Further, atomic hydrogen diffuses from the semiconductor surface and is adsorbed by p-type and n-type impurities, thereby causing passivation in which carriers that have been generated up to that point are inactivated. The vicinity of the resonator end face where hydrogen passivation occurs is a region showing extremely high resistance, and the leakage current in the pn junction region near the resonator end face is significantly reduced.

As described above, the current non-injection region is formed in the vicinity of the cavity end face by the irradiation of atomic hydrogen using the hydrogen radical beam, and the light absorption loss and the temperature rise are small as compared with the prior art, and the completeness is much higher. It is possible to fabricate an end face non-excited structure with high height.

[0010]

According to the present invention, the processing characteristic for the semiconductor surface is used to improve the characteristic properties of the end face of the cavity of the semiconductor laser, thereby obtaining the low threshold operation and improving the high output characteristic. The operation of the surface treatment technique according to the present invention and the effect thereof are shown below.

At the cavity facet of the semiconductor laser device, a deep level peculiar to surface atoms is generated due to the adsorption of oxygen and the formation of dangling bonds, and the forbidden band width near the cavity facet is substantially narrow. Has become. As a result, the light generated inside the resonator is absorbed near the end face. Since light absorption near the end face causes a temperature rise, the forbidden band width near the end face is further reduced, and further positive feedback that strongly receives the light absorption occurs. Eventually, the end face of the resonator of the element is thermally melted and deteriorated, which has been a limitation for increasing the output.

Therefore, in the present invention, before applying the coating film to the cavity end face, a hydrogen radical beam having good process matching is introduced into the same device, and the atomic state with the following effects is continuously produced in that place. Hydrogen treatment and coating film formation were possible.

First, the surface treatment of atomic hydrogen reduces and desorbs oxygen atoms adhering to the end faces of the resonator, and the dangling bonds of the surface atoms adsorb hydrogen atoms to reduce the surface level. To do. This suppresses the reduction of the forbidden band width at the end face of the resonator, and substantially increases the forbidden band width to the same extent as inside the resonator. As a result, since the light absorption near the end face described above can be significantly reduced, it is possible to suppress the temperature rise of the active layer due to the reduction of the light absorption loss. That is, the thermal phenomenon of melt fracture at the end face is alleviated, which is extremely advantageous for improving high output characteristics.

Further, in the treatment of atomic hydrogen, the atomic hydrogen can be diffused and adsorbed and fixed not only on the surface but also to a predetermined depth by appropriately setting the treatment temperature and time. In the region where hydrogen is diffused, atomic hydrogen is adsorbed by the p-type and n-type impurities of the optical waveguide layer that are initially set to inactivate the carriers. Further, even for impurities not intentionally set, the generation of excess carriers is suppressed by the adsorption of hydrogen atoms. Therefore, formation of a deep level that becomes a trap for carriers is also prevented. These resonator at the end face neighborhood can accurately set too low change the carrier concentration to a predetermined depth, inside the resonator default value of at least 2 orders of magnitude lower 5 × 10 ¹⁵ than
It was possible to reduce the range of ~5 × 10 ¹⁶ cm ~ ^3. By forming this high resistance layer, a current non-injection region with a very small leakage current could be set.

Since the leakage current in this end face non-excited structure is very small, the threshold current of the device can be reduced to about half that of the device of the conventional structure. Further, since the cavity length region where the gain can be obtained is substantially shortened, the threshold current can be made smaller in the device structure of the present invention than in the case where the end face non-excited structure is not provided, which is also effective in this respect. It was

As described above, in the device of the present invention, the temperature rise in the active layer in the vicinity of the end face of the resonator is 1 / th that of the conventional example.
It could be reduced to 4 to 1/5. The optical output current characteristics do not show rapid deterioration due to end face destruction, and the application of the coating film increases the maximum optical output by a factor of 2 to 3 compared to the device without the end face non-excitation structure. The device has a high output operation that is 1.6 to 1.8 times higher than that of the device having the excitation structure.

[0017]

【Example】

(Embodiment 1) An embodiment of the present invention will be described with reference to FIGS. In FIG. 1, first, an n-type GaAs tilt substrate 1 which is turned off by 5 ° in the [011] direction from the (100) plane is used, and an n-type Ga _0.51 In _0.49 P buffer layer 2 (d = 0.5 μ) is formed thereon.
_{m, n D = 1 × 10} 18 cm ~ 3), n -type (Al _y Ga _1-y)
0.51 In _0.49 P optical waveguide layer 3 (d = 1.6 μm, n _D = 5 ×
Compressive strain undoped (Al _x1 Ga ₁ -x1) _z In ₁ -z P (x ₁ = 0, 0.0) with a thickness of 10 ¹⁷ cm to ³ , y = 0.7) and a film thickness of 5 to 9 nm.
30 ≦ z ≦ 0.45) Two quantum well layers and a film thickness of 5 to 10 n
m unstrained undoped (Al _x2 Ga _1-x2 ) _0.51 In _0.49 P (x ₂ = 0.5) 5 to 30 nm thick unstrained undoped (Al _x2 Ga) layer on both sides of the quantum barrier layer and the quantum well layer.
_1-x2 ) _0.51 In _0.49 P (X ₂ = 0.5) Compressive strain multiple quantum well structure active layer 4 provided with an optical isolation confinement layer 4, p-type (Al
_y Ga _{1 -y} ) _0.51 In _0.49 P optical waveguide layer 5 (d = 1.3 μ
m, n _A = 7 to 9 × 10 ¹⁷ cm to ³ , y = 0.7), p-type Ga
_0.51 In _0.49 P buffer layer 6 (d = 0.05 μm, n _A
= 2 × 10 ¹⁸ cm ³ ) was epitaxially grown at a growth temperature of 750 ° C. by a metal organic chemical vapor deposition method. After this,
A SiO ₂ mask (film thickness d = 0.
2 .mu.m, stripe width 4 to 6 .mu.m), and the layer 6 and the layer 5 are removed by chemical etching until the layer 5 is 0.15 to 0.20 .mu.m to form a ridge stripe. Next, leaving the SiO ₂ mask,
n-type GaAs current constriction and light absorption layer 7 (d = 1.2 μm,
Selectively grow n _D = 2 × 10 ¹⁸ cm ³ ). Further, p-type GaAs contact layer 8 (d = 2 to 3 μm, n _A = 5 ×
10 ¹⁸ to 1 × 10 ¹⁹ cm ³ ) is buried and grown, and then the p-side electrode 9 and the n-side electrode 10 are vapor-deposited. Further, it is cleaved and cut into a bar-shaped element.

After that, a bar-shaped element sample is set in the RF sputtering apparatus, and the end faces of the resonator are irradiated with a hydrogen radical beam. As a result, p-type and n-type carriers were deactivated by atomic hydrogen in the vicinity of the resonator end face in the shaded area in FIG. As a result, the carrier concentration at 0.5 to 1.0 μm in the vicinity of the cavity facet is nearly 2 orders of magnitude lower than the initially set internal value, and the carrier concentration in the range of 5 × 10 ^{15 to} 5 × 10 ¹⁶ cm to ³ The leakage current flowing in the vicinity of the cavity facet was very small and could be reduced to a level estimated in the range of 100 μA to 1 mA. In this way, after the end face non-excited structure in which the current non-injection region is provided in the vicinity of the end face of the resonator is manufactured, the end face protective film having the front face reflectance of 10% and the rear face reflectance of 90% is continuously formed. After that, the element was scribed and cut out.

In this embodiment, the threshold current at room temperature is 30 to 40 mA in the element having the resonator length of 700 μm, which is less than half that of the element having the end face non-excitation structure of the prior art. This device did not show rapid deterioration due to end face destruction, and achieved high output operation with a maximum light output of 200 to 250 mW. This light output was 2-3 times higher than that of the device having no end face non-excited structure, and 1.6 to 1.8 times higher than that of the conventional device having the end face non-excited structure. The oscillation wavelength of this device is 675 to 685 at an optical output of 100 mW.
It was in the range of nm.

(Embodiment 2) Another embodiment of the present invention will be described with reference to FIGS. In FIG. 3, first, n-type GaAs (5
11) A tilted substrate 11 is used, on which n-type Ga _{0.51 is formed.}
In _0.49 P buffer layer 2 (d = 0.5 μm, n _D = 1 ×
10 ¹⁸ cm ~ ^3), n-type _{(Al y Ga 1-y)} 0.51 In 0.49 P optical waveguide layer _{3 (d = 1.6μm, n D} = 5 × 10 17 cm ~ 3, y
= 0.7), film thickness 8-15 nm tensile strain undoped (A
l _x1 Ga _1-x1 ) _z In _1-z P (x ₁ = 0, 0.55 ≦ z ≦ 0.
70) the quantum well layer 2 layer and the thickness 5~10nm of no strain undoped _{(Al x2 Ga 1-x2)} 0.51 In 0.49 P (x 2 = 0.5) quantum barrier layer first layer and a thickness of 20 to the quantum well both sides -40 nm unstrained undoped (Al _x2 G
a _{1-x 2} ) _0.51 In _0.49 P (x ₂ = 0.5) tensile-strained multiple quantum well structure active layer 12 provided with an optical isolation confinement layer, p-type (A
_{l y Ga 1-y) 0.51} In 0.49 P optical waveguide layer 5 (d = 1.3μm,
n _A = 7 to 9 × 10 ¹⁷ cm to ³ , y = 0.7), p-type Ga _0.51
In _0.49 P buffer layer 6 (d = 0.05 μm, n _A = 2
X10 ¹⁸ cm ³ ) was epitaxially grown at a growth temperature of 750 ° C. by a metal organic chemical vapor deposition method.

Thereafter, a bar-shaped element was manufactured in exactly the same manner as in Example 1, and a hydrogen radical beam was applied to the resonator end face in the same manner as in Example 1, indicated by the hatched lines in FIG. P-type and n
The carrier of the mold layer was deactivated. In this way, after the end face non-excited structure in which the current non-injection region is provided in the vicinity of the end face of the resonator is manufactured, the end face protective film having the front face reflectance of 10% and the rear face reflectance of 90% is continuously formed. After that, the element was scribed and cut out.

In this embodiment, the threshold current at room temperature is 40 to 50 mA in an element having a resonator length of 700 μm, which is less than half that of an element having an end face non-excitation structure according to the prior art. This device did not show rapid deterioration due to end face destruction, and achieved high output operation with a maximum light output of 100 to 150 mW. The light output was 2-3 times higher than that of the device having no end face non-excited structure, and 1.6 to 1.8 times higher than that of the device having the end face non-excited structure. The oscillation wavelength of this device is 625 to 625 at an optical output of 100 mW.
It was in the range of 635 nm.

(Embodiment 3) Another embodiment of the present invention will be described with reference to FIGS. In FIG. 5, first, n-type GaAs (5
11) A tilted substrate 11 is used, on which Cl-doped n
-Type ZnSe buffer layer 13 (d = 0.1 μm, n _D = 1 ×
10 ¹⁸ cm ~ ³ ), Cl-doped n-type Mg _y Zn _1-y S _z Se _1-z
Optical waveguide layer 14 (d = 1.5 μm, n _D = 5 × 10 ¹⁷ cm
³ , y = 0.10 to 0.12, z = 0.12 to 0.15),
Undoped Cd _x Zn _1-x Se / ZnS _z Se _1-z strained quantum well structure active layer 15 (ZnS _z Se _1-z quantum barrier layer (d = 4
nm, z = 0.06 to 0.08) 2 periods and Cd _x Zn _1-x Se compressive strain quantum well layer (d = 6 nm, x = 0.1) 3 periods and ZnS _z Se _1-z optical separation on both sides thereof Confinement layer (d = 30n
m, z = 0.06 ~0.08)) , N -doped p-type Mg _y Z
n _1-y S _z Se _1-z optical waveguide layer 16 (d = 1.2 μm, n _A =
4 to 7 × 10 ¹⁷ cm to ³ , y = 0.10 to 0.12, z = 0.
12-0.15), N-doped p-type ZnS _z Se _1-z optical waveguide layer 1
7 (d = 0.2 μm, n _A = 8 × 10 ¹⁷ to 1 × 10 ¹⁸ cm
~ ³ , z = 0.06 to 0.08), N-doped p-type ZnSαTe _1-
α buffer layer 18 (d = 0.05 to 0.1 μm, n _A = 1
^{~3 × 10 18 cm ~ 3,} α = 0.62~0.64) sequentially molecular beam epitaxy - epitaxially grown at the growth temperature of 300 ° C. by (MBE) method. Then, after depositing a SiN insulating film (d = 0.2 to 0.3 μm), the layer 16 has a thickness of 0.15 to 0.15 by photolithography and chemical etching.
Layer 20, layer 17 and layer 16 are removed to a depth of 0.20 μm to form a ridge stripe mesa (width 4 to 6 μm).

Next, with the SiN mask left, the n-type ZnSαTe _1- α current confinement and light absorption layer 19 (d = 1) is formed by the gas source molecular beam epitaxy (GSMBE) method or the metal organic chemical vapor deposition (MOCVD) method. 0.5-3.0 μm, n _D = 1-3
× 10 ¹⁸ cm ^-3 , α = 0.62-0.64) is selectively grown to bury the stripe structure flatly. Next, the SiN mask is removed by etching, and then N-doped p-type Z is formed by the MBE method.
nSαTe _1- α contact layer 20 (d = 20 to 50n
m, n _A = 3 × 10 ¹⁸ to 2 × 10 ¹⁹ cm to ³ , α gradually decreases from 0.63 to 0 toward the electrode 10 from the layer 7, and the surface in contact with the electrode 21 is N-doped p-type A ZnTe contact layer (n _A = 2 × 10 ¹⁹ cm to ³ ) is epitaxially grown. After this, the p-side electrode PdPtAu21 and the n-side electrode Au
GeNi22 is vapor-deposited, and cleaved and scribed to cut out into the shape of the element shown in the sectional view of FIG. After that, a bar-shaped element was produced in exactly the same manner as in Example 1, and the end faces of the resonator were irradiated with hydrogen radical beams in the same manner as in Example 1,
Carriers in the p-type and n-type layers were inactivated in the vicinity of the resonator end face in the shaded portion in FIG. In this way, after the end face non-excited structure in which the current non-injection region is provided in the vicinity of the end face of the resonator is manufactured, the end face protective film having the front face reflectance of 10% and the rear face reflectance of 90% is continuously formed. After that, the element was scribed and cut out.

In the present example, the threshold current at room temperature was 40 to 50 mA in the device having the resonator length of 700 μm, and the average value thereof was obtained to be somewhat lower than that of the device having no end face non-excitation structure. This device did not show rapid deterioration due to end face destruction, and achieved high output operation with a maximum light output of 100 to 150 mW. The light output was 2-3 times higher than that of the device having no end face non-excited structure, and 1.6 to 1.8 times higher than that of the device having the end face non-excited structure. The oscillation wavelength of this device is 5 at an optical output of 100 mW.
It was in the range of 20 to 530 nm.

(Embodiment 4) Another embodiment of the present invention will be described with reference to FIGS. In FIG. 7, first, n-type InP (51
1) Cl-doped n-type MgSe using A-angle substrate 23
Buffer layer 24 (d = 0.1 μm, n _D = 1 × 10 ¹⁸ cm
~ ³ ), Cl-doped n-type Mg _z Zn _1-z Se optical waveguide layer 25
(d = 1.5 μm, n _D = 5 × 10 ¹⁷ cm ~ ³ , z = 0.88
~ 0.92), undoped Cd _x Zn _1-x Se / ZnSe _y
Te _1-y strained quantum well structure active layer 26 (ZnSe _y Te _1-y
One quantum barrier layer (d = 4 nm, y = 0.45 to 0.50) and Cd _x Zn _1-x Se tensile strain quantum well layer (d = 10 nm,
x = 0.3) 2 periods and ZnSe _y Te _1-y optical separation confinement layers (d = 30 nm, y = 0.45 to 0.5) on both sides thereof.
0)), N-doped p-type Mg _z Zn _1-z Se optical waveguide layer 27 (d = 1.2 μm, n _A =
4-5 × 10 ¹⁷ cm- ³ , z = 0.88-0.92), N-doped p-type ZnSe _y Te ₁ - _y optical waveguide layer 28 (d = 0.2 μm,
n _A = 8 × 10 ¹⁷ cm to ³ , y = 0.45 to 0.50), N-doped p-type ZnSαTe _1- α buffer layer 29 (d = 0.1 μm, n _A
= 1 to 3 × 10 ¹⁸ cm ³ and α = 0.30 to 0.32) are sequentially epitaxially grown by the MBE method. Then Si
After depositing an N insulating film (d = 0.2 to 0.3 μm), a layer 27 is formed by photolithography and chemical etching.
Layer 29 and layer 28 to the place where 0.15 to 0.20 μm remains.
And the layer 27 are removed, and the ridge stripe mesa (width 4 to
6 μm) is formed.

Next, with the SiN mask left, GSM
N-type ZnSαTe _1- α by BE method or MOCVD method
Light absorption and current confinement layer 30 (d = 0.8 to 1.0 μm, n _A
= 1 to 3 × 10 ¹⁸ cm ³ and α = 0.30 to 0.32) are selectively grown to bury the stripe structure flatly. Next, SiN
After the mask is removed by etching, N-doped p is formed by the MBE method.
Type ZnSαTe _1- α contact layer 31 (d = 20 to 50)
nm, n _A = 3 × 10 ¹⁸ to 2 × 10 ¹⁹ cm to ³ , α is the layer 29
From 0.30 to 0 towards electrode 32,
An N-doped p-type ZnTe contact layer (n _A = 2 × 10 ¹⁹ cm to ³ ) is epitaxially grown on the surface in contact with the electrode 32. After this, the p-side electrode PdPtAu32 and the n-side electrode
AuGeNi33 is vapor-deposited, and cleaved and scribed to cut into the shape of the element shown in the sectional view of FIG.

After that, a bar-shaped element was manufactured in exactly the same manner as in Example 1, and a hydrogen radical beam was applied to the end faces of the resonator in the same manner as in Example 1, indicated by the diagonal lines in FIG. P-type and n
The carrier of the mold layer was deactivated. In this way, after the end face non-excited structure in which the current non-injection region is provided in the vicinity of the end face of the resonator is manufactured, the end face protective film having the front face reflectance of 10% and the rear face reflectance of 90% is continuously formed. After that, the element was scribed and cut out.

In the present example, the threshold current at room temperature was 30 to 40 mA in the device having the resonator length of 700 μm, and the average value was obtained to be somewhat lower than that of the device having no end face non-excitation structure. This device did not show rapid deterioration due to end face destruction, and achieved high output operation with a maximum light output of 150 to 200 mW. The light output was 2-3 times higher than that of the device having no end face non-excited structure, and 1.6 to 1.8 times higher than that of the device having the end face non-excited structure. The oscillation wavelength of this device is 5 at an optical output of 100 mW.
It was in the range of 20 to 530 nm.

[0030]

According to the present invention, by irradiating the end facet of the cavity of the semiconductor laser with the hydrogen radical beam, carrier passivation of atomic hydrogen is caused in the vicinity of the end facet, and end face non-excitation having a current non-injection region is caused. The structure could be made. The p-type and n-type carrier concentrations in the vicinity of the cavity facet are the internal initially set value of 5 × 10
5 to 10 which is lower than the range of ^{17 to} 2 x 10 ¹⁸ cm to ³ by almost 2 digits
^It was reduced to the range of ^{15 to} 5 × 10 ¹⁶ cm to ³ , and the leakage current flowing in the vicinity of the cavity facet could be reduced to a very small range of 100 μA to 1 mA. As a result, the temperature rise of the active layer in the vicinity of the end face of the cavity can be suppressed, and the optical loss of the end face non-excited structure can be set to a value that can be almost ignored without narrowing the forbidden band width in that region. In the device of the present invention, the threshold current is reduced and the maximum optical output is 2 as compared with the device having the same resonator length without the end face non-excitation structure.
.About.3 times, and the light output can be increased by 1.6 to 1.8 times as compared with the device having the end face non-excitation structure according to the prior art.

For the examples of the present invention, another material system A
lGaAs / GaAs, InGaAs / GaAs, InGa
It can also be applied to AsP / InP and InGaN / AlGaN systems.

[Brief description of drawings]

FIG. 1 is a sectional view of an element showing an embodiment of the present invention.

FIG. 2 is a sectional view of a resonator showing an embodiment of the present invention.

FIG. 3 is a sectional view of an element showing a second embodiment of the present invention.

FIG. 4 is a sectional view of a resonator showing a second embodiment of the present invention.

FIG. 5 is a sectional view of an element showing a third embodiment of the present invention.

FIG. 6 is a sectional view of a resonator showing a third embodiment of the present invention.

FIG. 7 is a sectional view of an element showing a fourth embodiment of the present invention.

FIG. 8 is a sectional view of a resonator showing a fourth embodiment of the present invention.

[Explanation of symbols]

1 ... 5 ° off n-type GaAs tilt substrate, 2 ... n-type GaIn
P buffer layer, 3 ... n-type AlGaInP optical waveguide layer, 4 ...
GaInP / AlGaInP compressive strain multiple quantum well structure active layer, 5 ... p-type AlGaInP optical waveguide layer, 6 ... p-type Ga
InP buffer layer, 7 ... N-type GaAs current constriction and light absorption layer, 8 ... P-type GaAs contact layer, 9 ... P-side electrode.

Claims (6)

[Claims] 1. A semiconductor having a heterojunction structure in which a light emitting active layer having a small forbidden band formed on a semiconductor substrate is sandwiched between optical waveguide layers having a large forbidden band having different conductivity types on both sides. In a laser device, the resonator end face when forming a horizontal or vertical resonator of laser light is irradiated with a hydrogen radical beam in a high vacuum device to diffuse atomic hydrogen into the end face and the semiconductor near the end face. Adsorbing, binding atomic hydrogen to a pre-introduced impurity exhibiting a conductivity type, and setting the p-type and n-type carrier concentrations in the end face and in the vicinity of the end face to be lower than the value inside the resonator that is initially set, In the same device that subsequently irradiates the hydrogen radical beam, a high thermal conductivity coating is applied in-situ.
A method for manufacturing a semiconductor laser device, which comprises forming an end face protective film having a predetermined reflectance. 2. The carrier concentration for p-type and n-type carriers set in the optical waveguide layer according to claim 1 is 5 × 10.
After irradiating the hydrogen radical beam to the cavity end face region in the range of ^{17 to} 2 × 10 ¹⁸ cm to ³ , atomic hydrogen is bound to the previously introduced impurities showing p-type and n-type. By inactivating the carriers in the vicinity of the end face of the resonator, the p-type or n-type carrier concentration in the end face and in the vicinity of the end face is 5 × 10 ^{15 to} 5 × 10 lower than that of the optical waveguide layer inside the resonator by almost two digits. ^A method for manufacturing a semiconductor laser device having a range of ¹⁶ cm to ³ . 3. The method according to claim 1 or 2, wherein when atomic hydrogen is diffused and adsorbed in the semiconductor on the end face and in the vicinity of the end face by irradiation with a hydrogen radical beam, the atomic hydrogen binds to an impurity exhibiting a conductivity type. , The p-type and n-type carrier concentrations in the region near the end face are nearly two orders of magnitude lower than the inside of the resonator that is initially set, and a range in the depth direction occurs from the end face to 0.05 to 2.0 μm. However, the method for manufacturing a semiconductor laser device preferably has 0.5 μm or more from the end face. 4. The temperature of a sample as set forth in claim 1, 2, or 3 when the hydrogen radical beam is irradiated.
A method for manufacturing a semiconductor laser device, wherein the temperature is set to 50 ° C., and preferably set to 300 to 400 ° C. 5. The method according to claim 1, 2, 3, or 4, wherein
In the group-V semiconductor, B is used as an impurity exhibiting p-type conductivity.
One of e, Mg, and Zn is used, and Si is used as the n-type impurity. In the II-VI semiconductor, N is used as the p-type impurity.
And a method of manufacturing a semiconductor laser device using any of Cl, Br, and I as an n-type impurity. 6. The method according to claim 1, 2, 3, 4 or 5.
The semiconductor substrate used has a substrate plane orientation in the range of 0 ° to 54.7 ° from the (100) plane, preferably larger than 0 °.
A method of manufacturing a semiconductor laser device having a substrate surface inclined by 25.2 ° or less corresponding to the (311) plane.