JPH05291679A - Semiconductor laser - Google Patents

Abstract

PURPOSE:To improve current confining characteristics in a semiconductor laser having an active layer formed continuously from a light emitting region to an adjacent region. CONSTITUTION:A semiconductor laser has an active layer 6 formed continuously from a light emitting region to an adjacent region and interposed between a first conductivity type clad layer 5 and a second conductivity type clad layer 7. A first conductivity type high resistance spacer layer 9 having higher resistivity than that of the layer 5 is inserted into the layer 5. The thickness of the layer 9 is thinner in a region corresponding to the light emitting region of the layer 6, and thicker in a region corresponding to the adjacent region of the layer 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor laser device, and more particularly, an active layer formed continuously from a light emitting region to an adjacent region is sandwiched between a first conductivity type clad layer and a second conductivity type clad layer. The present invention relates to a semiconductor laser device. Among the semiconductor laser devices, the AlGaInP-based transverse mode control type visible light laser device of the 0.6 μm band is highly expected as a light source in order to realize high performance of optical information processing devices such as POS, optical disk devices, and laser printers. There is.

A visible light semiconductor laser device of such an optical information processing device is required to have characteristics of high efficiency and high output with a low threshold current.

[0003]

2. Description of the Related Art Generally, it is known that it is very difficult to grow a material containing Al on a layer containing Al except for the case where the material is continuously formed in the same apparatus. Therefore, in the AlGaInP-based semiconductor laser device, Ga
Unlike the semiconductor laser device of As / AlGaAs system,
It was difficult to achieve a change in refractive index by embedding a material containing Al.

Therefore, in the conventional AlGaInP semiconductor laser, various measures have been taken to control the transverse mode. FIG. 4 shows a conventional AlGaI controlled in transverse mode.
An nP semiconductor laser device is shown (Japanese Patent Laid-Open No. 62-2007).
No. 86). n-AlGa on the n-type GaAs substrate 21
The n-side cladding layer 22 made of InP is formed, the active layer 23 made of GaInP is formed on the n-side cladding layer 22, and the p-side first cladding layer 24 made of p-AlGaInP is formed on the active layer 23. There is. The surface is flat up to the p-side first cladding layer 24.

On the p-side first cladding layer 24, p-Ga is formed.
P side etching stop layer 25 made of InP, p-A
p-side second cladding layer 26 made of lGaInP, p-G
p-side spike prevention layer 27 made of aInP, p-GaI
A p-side first contact layer 28 made of nP is stacked, and its cross section is formed in a mesa stripe shape. This mesa stripe is an n-type current blocking layer 2 made of n-GaAs.
9, a p-side second contact layer 30 made of p-GaAs is formed on the p-side first contact layer 28 and the n-type current blocking layer 29.

As described above, in the AlGaInP semiconductor laser device shown in FIG. 4, only the p-side second cladding layer 26, which is the upper cladding layer, is formed in a stripe shape to change the refractive index in the lateral direction. However, since the n-type current blocking layers 29, which are buried layers on both ends of the mesa stripe shape, are made of GaAs that absorbs light and have a loss guide structure, a semiconductor laser device having high quantum efficiency can be obtained. There was a problem that it was difficult.

On the other hand, it is known that when a double hetero structure is formed on a substrate having a step, the active layer has a step and the lateral mode control of the semiconductor laser device becomes possible. The inventor of the present application has proposed an AlGaInP-based semiconductor laser device that performs transverse mode control in this manner (Japanese Patent Application No. 2-159997). A semiconductor laser device proposed by the present inventor is shown in FIG.

A mesa stripe shape is formed on the surface of the p-type GaAs substrate 1. The mesa stripe shape of the p-type GaAs substrate 1 is filled with the n-type current block layer 2 made of n-GaAs, and the slope of the mesa stripe shape is a gentle slope. On the p-type GaAs substrate 1 and the n-type current blocking layer 2, a buffer layer 3 made of p-GaAs, p- (Al _0.1 Ga _0.9 ) _0.5 In _0.5 P to p- is formed.
(Al _0.7 Ga _0.3 ) _0.5 In _0.5 P p-side spike prevention layer 4 whose composition gradually changes, p- (Al _0.7 G
a _0.3 ) _0.5 In _0.5 P p-side cladding layer 5, G
active layer 6 made of _{a 0.4 In 0. 6 P, n-} (Al 0.7 G
a _0.3 ) _0.5 In _0.5 P, the n-side cladding layer 7 is
It is laminated in a shape along the mesa stripe shape. n
A contact layer 8 made of n-GaAs is formed on the side cladding layer 7.

As described above, in the semiconductor laser device shown in FIG. 5, lateral mode control of light is performed by the curved active layer 6. Therefore, it is not necessary to consider the absorption loss of light instead of the loss guide structure.

[0010]

However, in the semiconductor laser device shown in FIG. 5, since the n-type current blocking layer 2 for current confinement is separated from the active layer 6, the buffer layer 3 and the p-side spike prevention layer are provided. 4, the current spreads in the p-side clad layer 5, there is a problem in the current confinement characteristic, and there is a problem that desired characteristics cannot be obtained as a semiconductor laser device.

An object of the present invention is to provide a semiconductor laser device having improved current confinement characteristics.

[0012]

The above object is to provide a semiconductor laser in which an active layer formed continuously from a light emitting region to an adjacent region is sandwiched between a first conductivity type cladding layer and a second conductivity type cladding layer. In the device, a first conductivity type high resistance spacer layer having a higher resistivity than the first conductivity type clad layer is inserted into the first conductivity type clad layer, and the film thickness of the high resistance spacer layer is the active layer. This is achieved by a semiconductor laser device characterized by being thin in a region corresponding to a light emitting region of the layer and thick in a region corresponding to a region adjacent to the active layer.

The above object is to provide a semiconductor laser device in which an active layer formed continuously from a light emitting region to an adjacent region is sandwiched between a first conductivity type cladding layer and a second conductivity type cladding layer. A second layer is provided between the conductive clad layer and the active layer.
A conductive type remote junction layer is inserted, and the film thickness of the remote junction layer is formed in a region in contact with the light emitting region of the active layer and between the active layer and the active layer at the time of current injection. The semiconductor laser device is characterized in that it is thinner than the depletion layer and is thicker than the depletion layer in a region in contact with a region adjacent to the active layer.

[0014]

According to the present invention, the first-conductivity-type high-resistance spacer layer having a higher resistivity than the first-conductivity-type clad layer is inserted into the first-conductivity-type clad layer, and the thickness of the high-resistance spacer layer is increased. However, since the thickness is thin in the region corresponding to the light emitting region of the active layer and thick in the region corresponding to the adjacent region of the active layer, the resistance is higher in the adjacent region than in the light emitting region of the active layer and the current Current becomes difficult to flow and current can be concentrated in the light emitting region of the active layer.

Further, according to the present invention, a second conductivity type remote junction layer is inserted between the first conductivity type cladding layer and the active layer, and the thickness of the remote junction layer is
In the region in contact with the light emitting region of the active layer, thinner than the thickness of the depletion layer formed between the active layer and the active layer at the time of current injection into the light emitting region, and in the region in contact with the adjacent region of the active layer, the depletion layer Since the thickness is made thicker than the thickness, based on the thickness difference of the remote junction layer, only the remote junction layer adjacent to the active layer has a portion that is not depleted, and this portion functions as the current block layer. The current can be concentrated in the light emitting region of the active layer.

[0016]

EXAMPLE A semiconductor laser device according to a first example of the present invention will be described with reference to FIG. The same components as those of the semiconductor laser device shown in FIG. 5 are designated by the same reference numerals to omit or simplify the description. Zn doped with an impurity concentration of 1 × 1
On the surface of the p-type GaAs substrate 1 of 0 ¹⁹ cm ^-3 , about 1.8 μm
A mesa stripe shape having a height of m is formed. p-type G
The mesa stripe shape of the aAs substrate 1 is filled with an n-type current block layer 2 of about 1 μm thickness made of n-GaAs doped with Se and having an impurity concentration of 2 × 10 ¹⁸ cm ⁻³ , and the slope of the mesa stripe shape is gentle. It is a slope.

P-type GaAs substrate 1 and n-type current block
Zn is doped on the layer 2 so that the impurity concentration is 6 × 10.¹⁶
cm^-350nm thick buffer made of p-GaAs
Layer 3, Mg doped, impurity concentration 3 × 10¹⁷cm^-3
And p- (Al_0.1Ga_0.9) _0.5In_0.5P to p-
(Al_0.7Ga_0.3)_0.5In_0.5The composition gradually changes to P
The p-side spike prevention layer 4 having a thickness of about 0.1 μm and Mg
Doped impurity concentration is 5 × 10¹⁷cm^-3P- (Al
_0.7Ga_0.3)_0.5In_0.5About 0.5 μm thick made of P
P-side clad layer 5 has a shape along the mesa stripe shape
Are stacked on.

On the p-side clad layer 5, Mg-doped p- (Al _0.7 Ga) having an impurity concentration of 2 × 10 ¹⁷ cm ^-3 is formed.
_0.3 ) _0.5 In _0.5 P p-type high resistance spacer layer 9
Are formed. The p-type high resistance spacer layer 9 is p
It has a specific resistance of 2.0 to 2.5 Ω · cm, which is higher than that of the side clad layer 5, and the flat portion in the center of the mesa stripe shape has a film thickness of 0.1 μm, while the adjacent gentle slope is closer. Is formed so that the film thickness becomes as thick as 0.2 μm.

On the p-type high resistance spacer layer 9, an active layer 6 made of undoped Ga _0.4 In _0.6 P and having a thickness of about 0.08 μm, Se is doped and the impurity concentration is 8 × 10 ¹⁷ cm.
^-3 n- (Al _0.7 Ga _0.3 ) _0.5 In _0.5 P and an n-side clad layer 7 having a thickness of about 0.6 μm is formed along the mesa stripe shape. Se is doped on the n-side cladding layer 7 to have an impurity concentration of 2 × 10 ¹⁸ cm ^−3.
The contact layer 8 made of n-GaAs is formed on the entire surface.

As described above, according to this embodiment, the p-type high-resistance spacer layer 9 formed on the p-side cladding layer 5 has a high resistance, and the gently-sloping surface adjacent to the flat portion in the center of the mesa stripe shape is adjacent. Since the film is formed so as to have a large thickness above, the resistance is higher in the region adjacent to the active layer 6 and it is difficult for current to flow, so that the current can be concentrated in the light emitting region in the center of the active layer 6.

In the semiconductor laser device of this embodiment, a guide layer (not shown) made of Se-doped n-AlGaInP and having a thickness of about 0.3 μm is provided between the active layer 6 and the n-side cladding layer 7. May be provided. Further, an n-side spike prevention layer (not shown) made of n-GaInP may be provided between the n-side cladding layer 7 and the contact layer 8. Next, a method of manufacturing the semiconductor laser device of this embodiment will be described.

First, a silicon oxide film (not shown) is deposited on the p-type GaAs substrate 1 by sputtering, and the silicon oxide film is patterned so as to form stripe-shaped openings. Next, the p-type GaAs substrate 1 is etched by using the silicon oxide film as a mask, and the (111)
A mesa stripe shape having a depth of 1.8 μm is formed so that the B surface appears.

Next, Se is doped by the MOVPE method.
The impurity concentration is 2 × 10¹⁸cm^-3From n-GaAs
The n-type current blocking layer 2 having a thickness of about 1 μm is formed of p-type GaAs.
Grows on the substrate 1 and fills the mesa stripe. next,
The silicon oxide film is stripped with an HF solution. Next, MO
By the VPE method, the p-type GaAs substrate 1 and the n-type current block are
The Zn layer is doped with Zn and the impurity concentration is 6 × 10
¹⁶cm^-3About 50 nm thick p-GaAs buffer
Layer 3, Mg is doped and the impurity concentration is 3 × 10¹⁷cm
^-3And p- (Al_0.1Ga_0.9)_0.5In_0.5P to p-
(Al_0.7Ga_0.3)_0.5In_0.5The composition gradually changes to P
The p-side spike prevention layer 4 having a thickness of about 0.1 μm and Mg
Doped impurity concentration is 5 × 10¹⁷cm^-3P- (Al
_0.7Ga_0.3)_0.5In_0.5About 0.5 μm thick made of P
Of the p-side clad layer 5 of Mg and the impurity concentration of 2
× 10¹⁷cm^-3P- (Al_0.7Ga_0.3)_0.5In
_0.5P type high resistance spacer layer 9 made of P, undoped
Ga_0.4In_0.6An active layer of P having a thickness of about 0.08 μm
6, Se doped, impurity concentration 8 × 10¹⁷cm^-3of
n- (Al _0.7Ga_0.3)_0.5In_0.5About P
0.6 μm thick n-side clad layer 7, Se is not doped
Pure substance concentration is 2 × 10¹⁸cm^-3Of n-GaAs
The contact layer 8 is sequentially formed.

The buffer layer 3, the p-side spike prevention layer 4, the p-side cladding layer 5, the p-type high resistance spacer layer 9, the active layer 6, and the n-side cladding layer 7 are formed according to the crystal plane of the underlying layer. The flat portion at the center of the mesa stripe is thin and the slope portion is thick. A semiconductor laser device according to the second embodiment of the present invention will be described with reference to FIG. The same components as those of the semiconductor laser device of the first embodiment shown in FIG. 1 are designated by the same reference numerals to omit or simplify the description.

A mesa stripe shape is formed on the surface of the p-type GaAs substrate 1. This mesa stripe shape is filled with the n-type current block layer 2, and the slope of the mesa stripe shape is a gentle slope. A buffer layer 3, a p-side spike prevention layer 4, and a p-side clad layer 5 are laminated on the p-type GaAs substrate 1 and the n-type current blocking layer 2 in a shape along a mesa stripe shape.

An undoped n layer is formed on the p-side cladding layer 5.
^--(Al_0.7Ga_0.3)_0.5In _0.5N type consisting of P
The remote junction layer 10 is formed. this
The n-type remote junction layer 10 is a mesa stripe
The flat part at the center of the shape has a film thickness of 0.1 μm.
However, the adjacent gentle slope has a thicker film thickness of 0.2 μm.
Is formed.

An active layer 6 is formed on the n-type remote junction layer 10. On the active layer 6, Se was doped and n- (Al with an impurity concentration of 1 × 10 ¹⁷ cm ⁻³ was used.
_An n-type high resistance spacer layer 11 made of _0.7 Ga _0.3 ) _0.5 In _0.5 P is formed. The n-type high resistance spacer layer 11 is formed such that the flat portion at the center of the mesa stripe shape has a film thickness of 0.1 μm, while the adjacent gentle slope has a film thickness of 0.2 μm. ing.

An n-side clad layer 7 is formed on the n-type high resistance spacer layer 11 in a shape along the mesa stripe shape, and a contact layer 8 is formed on the entire surface of the n-side clad layer 7. Thus, according to this embodiment, the active layer 6
The n-type remote junction layer 10 is joined to the p-side clad layer 5 side of
Is formed so that the flat portion at the center of the mesa stripe shape is thin and the adjacent gentle slope becomes thicker. Therefore, when a forward bias voltage is applied to the semiconductor laser device to inject a current into the active layer 6, a depletion layer is formed at the junction between the n-type remote junction layer 10 and the active layer 6, and the depletion layer is n. It also extends into the mold remote junction layer 10.

In this embodiment, the film thickness of the flat portion of the n-type remote junction layer 10 is made thinner than that of the depletion layer, and the film thickness of the gentle slope is made thicker than that of the depletion layer. Therefore, the n-type remote junction layer 10 is completely depleted in the flat portion and does not serve as a barrier against the injection current, but remains in the gentle slope portion as the n-type semiconductor layer that is not depleted, and thus serves as a barrier against the injection current. The current can be concentrated in the light emitting region at the center of the active layer 6.

In addition, when an AlGaInP-based compound semiconductor or the like is doped with impurities such as Zn, Si, and Se, non-luminous defects such as deep level are generated, and the luminous efficiency of the semiconductor laser device is reduced. Since the n-type remote junction layer 10 in contact with the active layer 6 is undoped as in the present embodiment, the light emission efficiency can be increased.

Further, according to this embodiment, the active layers 6 and n
The n-type high resistance spacer layer 11 formed between the side clad layer 7 and the side clad layer 7 has a high resistance, and is formed so that the film thickness becomes thicker on the gentle slope adjacent to the flat portion in the center of the mesa stripe shape. Since the resistance is higher in the region adjacent to the active layer 6 and the current does not flow easily, the current can be concentrated in the light emitting region at the center of the active layer 6.

A semiconductor laser device according to the third embodiment of the present invention will be described with reference to FIG. The same components as those of the semiconductor laser device of the second embodiment shown in FIG. 2 are designated by the same reference numerals to omit or simplify the description. p-type GaAs substrate 1
A mesa stripe shape is formed on the surface of, and the mesa stripe shape is filled with the n-type current block layer 2, and the slope of the mesa stripe shape is a gentle slope.

On the p-type GaAs substrate 1 and the n-type current blocking layer 2, the buffer layer 3, the p-side spike prevention layer 4, and p.
The side cladding layer 5 is laminated in a shape along the mesa stripe shape. On the p-side clad layer 5, Mg-doped p- (Al _0.7 G having an impurity concentration of 1 × 10 ¹⁷ cm ⁻³ is used.
The p-type high resistance spacer layer 12 made of a _0.3 ) _0.5 In _0.5 P is formed. This p-type high resistance spacer layer 12
Is higher than the p-side clad layer 5 and is 2.0 to 2.5 Ω · cm.
The thickness of the flat portion in the center of the mesa stripe shape is 0.1 μm, while the thickness of the adjacent gentle slope is 0.2 μm. There is.

An n-type remote junction layer 10 is formed on the p-type high resistance spacer layer 12, and an active layer 6 is formed on the n-type remote junction layer 10.
The active layer 6 is doped with Mg and has an impurity concentration of 1 × 1.
0 ¹⁷ cm ⁻³ p- (Al _0.7 Ga _0.3 ) _0.5 In _0.5 P
The p-type remote junction layer 13 is formed. The p-type remote junction layer 13 has a film thickness of 0.02 μm in the flat portion in the center of the mesa stripe shape.
In contrast, the adjacent gentle slope has a film thickness of 0.04
It is formed to have a thickness of μm.

An n-type high resistance spacer layer 11 is formed on the p-type remote junction layer 13. The n-type high resistance spacer layer 11 is formed such that the flat portion at the center of the mesa stripe shape has a film thickness of 0.1 μm, while the adjacent gentle slope has a film thickness of 0.2 μm. ing. An n-side clad layer 7 is formed on the n-type high resistance spacer layer 11 in a shape along the mesa stripe shape, and a contact layer 8 is formed on the entire surface of the n-side clad layer 7.

As described above, according to this embodiment, the n-type remote junction layer 1 is provided on the p-side cladding layer 5 side of the active layer 6.
0 is joined, and the p-type remote junction layer 13 is joined to the n-side cladding layer 7 side of the active layer 6, and these n-type remote junction layer 10 and p-type remote junction layer 13 have a flat portion in the center of the mesa stripe shape. It is thin and is formed so that the adjacent gentle slope becomes thicker.

Therefore, when a forward bias voltage is applied to the semiconductor laser device in order to inject a current into the active layer 6, n
A depletion layer is formed at the junction between the type remote junction layer 10 and the active layer 6 and at the junction between the active layer 6 and the p-type remote junction layer 13. In this embodiment, the film thickness of the flat portion of the n-type remote junction layer 10 and the p-type remote junction layer 13 is formed to be thinner than the thickness of the depletion layer, and the film thickness of the gentle slope is made thicker than the thickness of the depletion layer. To form. Accordingly, the flat portions of the n-type remote junction layer 10 and the p-type remote junction layer 13 are all depleted and do not serve as a barrier to the injection current, but are not depleted in the gentle slope portion. Since the layer remains, it becomes a barrier against the injected current, and the current can be concentrated in the light emitting region at the center of the active layer 6.

Further, according to this embodiment, the p-type high resistance spacer layer 12 is provided on the p-side cladding layer 5 side, and the n-type high resistance spacer layer 11 is provided on the n-side cladding layer 7 side. Since the resistance spacer layer 12 and the n-type high resistance spacer layer 11 are formed such that the film thickness becomes thicker on the gentle slope adjacent to the flat portion in the center of the mesa stripe shape, the region adjacent to the active layer 6 is However, the resistance becomes high and the current hardly flows, and the current can be concentrated in the light emitting region at the center of the active layer 6.

The present invention is not limited to the above embodiment, but various modifications can be made. For example, although the high resistance spacer layer is provided between the clad layer and the active layer in the above embodiment, it may be provided anywhere within the clad layer. Further, a high resistance spacer layer or a remote junction layer may be provided on one side of the active layer, a high resistance spacer layer and a remote junction layer may be provided on one side of the active layer, or a high resistance may be provided on both sides of the active layer. A spacer layer or a remote junction layer may be provided, or both the high resistance spacer layer and the remote junction layer may be provided on both sides of the active layer.

In the above embodiment, the AlGaInP-based semiconductor laser device is used, but it may be applied to an AlGaAs-based semiconductor laser device or an InGaAsP-based semiconductor laser device. Further, although the film thickness of the high resistance spacer layer and the remote junction layer is changed by utilizing the difference in the crystal plane of the base in the above-mentioned embodiment, the film thickness may be changed by another method.

[0041]

As described above, according to the present invention, a high resistance spacer layer of the first conductivity type having a higher resistivity than the first conductivity type clad layer is inserted into the first conductivity type clad layer, and the high resistance spacer layer is formed. Since the thickness of the resistive spacer layer is thin in the region corresponding to the light emitting region of the active layer and thick in the region corresponding to the adjacent region of the active layer, the resistance is higher in the adjacent region of the active layer and the current Current becomes difficult to flow and current can be concentrated in the light emitting region of the active layer.

According to the present invention, the second conductivity type remote junction layer is inserted between the first conductivity type cladding layer and the active layer, and the thickness of the remote junction layer is
In the region in contact with the light emitting region of the active layer, thinner than the thickness of the depletion layer formed between the active layer and the active layer during current injection into the light emitting region, and in the region in contact with the adjacent region of the active layer, the depletion layer Since it is made thicker than the thickness, only the remote junction layer adjacent to the active layer has a part that is not depleted, and this part functions as a current block layer to concentrate the current in the light emitting region of the active layer. You can

[Brief description of drawings]

FIG. 1 is a sectional view of a semiconductor laser device according to a first embodiment of the present invention.

FIG. 2 is a sectional view of a semiconductor laser device according to a second embodiment of the present invention.

FIG. 3 is a sectional view of a semiconductor laser device according to a third embodiment of the present invention.

FIG. 4 is a sectional view of a conventional semiconductor laser device.

FIG. 5 is a sectional view of a proposed semiconductor laser device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... p-type GaAs substrate 2 ... n-type current blocking layer 3 ... buffer layer 4 ... p-side spike prevention layer 5 ... p-side cladding layer 6 ... active layer 7 ... n-side cladding layer 8 ... contact layer 9 ... p-type high resistance Spacer layer 10 ... n-type remote junction layer 11 ... n-type high-resistance spacer layer 12 ... p-type high-resistance spacer layer 13 ... p-type remote junction layer 21 ... n-type GaAs substrate 22 ... n-side clad layer 23 ... active layer 24 ... p-side first cladding layer 25 ... p-side etching stop layer 26 ... p-side second cladding layer 27 ... p-side spike prevention layer 28 ... p-side first contact layer 29 ... n-type current blocking layer 30 ... p-side second contact layer

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Megumi Douen 1015 Kamiodanaka, Nakahara-ku, Kawasaki City, Kanagawa Prefecture, Fujitsu Limited (72) Inventor, Akira Furuya 1015, Kamedotachu, Nakahara-ku, Kawasaki City, Kanagawa Prefecture, Fujitsu Limited

Claims (3)

[Claims] 1. A semiconductor laser device in which an active layer formed continuously from a light emitting region to an adjacent region is sandwiched between a first conductivity type clad layer and a second conductivity type clad layer, wherein the first conductivity type is provided. A first conductivity type high resistance spacer layer having a resistivity higher than that of the first conductivity type clad layer is inserted into the clad layer, and the film thickness of the high resistance spacer layer corresponds to a light emitting region of the active layer. The semiconductor laser device is characterized in that it is thin and thick in a region corresponding to a region adjacent to the active layer. 2. The semiconductor laser device according to claim 1, wherein a first conductivity type remote junction layer is inserted between the active layer and the second conductivity type cladding layer, and the thickness of the remote junction layer is the active layer. In a region in contact with the light emitting region of the layer, the region is thinner than the thickness of the depletion layer formed between the active layer and the active layer at the time of current injection into the light emitting region of the active layer, and in a region in contact with the adjacent region of the active layer, A semiconductor laser device characterized by being thicker than a depletion layer. 3. A semiconductor laser device in which an active layer formed continuously from a light emitting region to an adjacent region is sandwiched between a first conductivity type clad layer and a second conductivity type clad layer, wherein the first conductivity type is provided. A second conductivity type remote junction layer is inserted between the clad layer and the active layer, and the film thickness of the remote junction layer is a region in contact with the light emitting region of the active layer when a current is injected into the light emitting region of the active layer. A semiconductor laser device characterized in that it is thinner than a depletion layer formed between the active layer and a region adjacent to the active layer and thicker than the depletion layer.