JP2006128449A - Semiconductor laser element and manufacturing method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a semiconductor laser element which prevents the formation of a void in a current block layer to offer fine laser characteristics, and to provide a manufacturing method for the semiconductor laser element. <P>SOLUTION: The semiconductor laser element comprises a cladding layer 3, an active layer 4, a first cladding layer 5, a ridge 8 consisting of a second cladding layer 7, and a cap layer 9. These are overlaid on a semiconductor board 2 in increasing order. The semiconductor laser element also includes the current block layer 10 which is on the first cladding layer 5 and sandwiches the ridge 8 and the cap layer 9, and a contact layer 12 which is formed on the cap layer 9 and the current block layer 10. The layers are so formed as to satisfy the inequality: W<SB>1</SB>>W<SB>2</SB>=W<SB>3</SB>, where W<SB>1</SB>is the width of the upper part of the cap layer 9, W<SB>2</SB>is the width of the lower part of the cap layer 9, and W<SB>3</SB>is the width of the upper part of the ridge 8. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a semiconductor laser device having low power consumption and high reliability, and a method for manufacturing the same.

As a semiconductor laser element having low power consumption and high reliability, there is one described in Patent Document 1.
The semiconductor laser element described in Patent Document 1 will be described below with reference to FIG.
As shown in FIG. 10, a conventional semiconductor laser device 17 includes an n-type GaAs buffer layer 18 on an n-type GaAs substrate 2 and an n-type Al _t Ga _1-t As (0.45 ≦ t ≦ 0.65) lower portion. cladding layer _{3, Al u Ga 1-u} As (0.07 ≦ u ≦ 0.65) active layer 4, p-type _{Al v Ga 1-v As (} 0.45 ≦ v ≦ 0.65) upper first cladding Layer 5 and p-type GaAs etching stop layer 19 are sequentially stacked.

On the p-type GaAs etching stop layer 19, a trapezoidal ridge portion 8 made of the p-type Al _x Ga _1-x As upper second cladding layer 7 is formed. On the ridge portion 8, a p-type GaAs cap layer 9 having an inverted mesa shape that is wider than the upper portion of the ridge portion 8 is formed. Further, on the p-type GaAs etching stop layer 19, the n-type Al _y Ga _1-y As current blocking layer 10 and the n-type GaAs protective layer 10 are sandwiched between the side surfaces of the ridge portion 8 and the p-type GaAs cap layer 9. The layer 11 and the p-type GaAs protective layer 20 are sequentially formed to form the same plane as the surface of the p-type GaAs cap layer 9.

Furthermore, a p-type GaAs contact layer 12 is formed on the n-type Al _y Ga _1-y As current blocking layer 10, the n-type GaAs protective layer 11, the p-type GaAs protective layer 20 and the p-type GaAs cap layer 9. ing.
A p-type ohmic electrode 13 is formed on the p-type GaAs contact layer 12, and an n-type ohmic electrode 14 is formed on the n-type GaAs substrate 2 opposite to the stacking direction. The ranges of t, u, v, x, and y are 0.45 ≦ t ≦ 0.65, 0.07 ≦ u ≦ 0.65, 0.45 ≦ v ≦ 0.65, 0.45 ≦ x. ≦ 0.65, 0.5 ≦ y ≦ 0.85.

When the upper width of the p-type GaAs cap layer 9 is W ₁ , the lower width is W ₂ , the thickness is d ₁ , and the upper width of the ridge portion 8 is W ₃ , (W ₁ −W ₃ ) / 2d ₁ <3 and 0.3 μm <W ₂ −W ₃ <3 μm. The p-type GaAs cap layer 9 has an angle formed between the side surface and the bottom surface of 90 ° or more. Thus, it is described that a low resistance semiconductor laser device 17 with improved crystallinity of the p-type GaAs contact layer 12 can be obtained.

Next, a conventional method for manufacturing a semiconductor laser device will be described with reference to FIGS.
As shown in FIG. 11, the first crystal growth is performed to form an n-type GaAs buffer layer 18, an n-type Al _t Ga _1-t As lower cladding layer 3, and Al _u Ga _1- on the n-type GaAs substrate 2. _u As active layer 4, p-type Al _v Ga _1-v As upper first cladding layer 5, p-type GaAs etching stop layer 19, p-type Al _x Ga _1-x As upper second cladding layer 7, p-type GaAs cap Layers 9 are sequentially stacked.
Next, as shown in FIG. 12, a striped photoresist pattern 15 is formed in the central portion of the p-type GaAs cap layer 9 by photolithography.

Next, as shown in FIG. 13, the p-type GaAs cap layer 9 to the p-type Al _x Ga _1-x As upper second cladding layer 7 in the region not covered with the photoresist pattern 15 are etched halfway. The etchant used at this time is an etchant (sulfuric acid: hydrogen peroxide solution: water = 1: 8: 50) that has a higher etching rate than AlGaAs than GaAs. Therefore, the width of the p-type GaAs cap layer 9 is The width of the p-type Al _x Ga _1-x As upper second cladding layer 7 can be made wider. Since this etchant has anisotropy in the etching rate with respect to GaAs, the p-type GaAs cap layer 9 has an inverted mesa shape in which the angle formed between the side surface and the bottom surface is 90 ° or more.

Next, as shown in FIG. 14, using an etchant having a slower etching rate than GaAs compared to AlGaAs, only the p-type Al _x Ga _1-x As upper second cladding layer 7 is subjected to HF etching solution. Etching is performed until the p-type GaAs etching stop layer 19 is reached, and a trapezoidal ridge portion 8 is formed.

Next, as shown in FIG. 15, after removing the photoresist pattern 15, the second crystal growth is performed, so that the n-type Al _y Ga _1-y As current blocking layer 10, the n-type GaAs protective layer 11, A p-type GaAs protective layer 20 is sequentially stacked.

  Next, as shown in FIG. 16, a photoresist pattern 16 having an opening at the center is formed on the p-type GaAs protective layer 20.

Next, as shown in FIG. 17, the n-type Al _y Ga _1-y As current blocking layer 10, the n-type GaAs protective layer 11, and the p-type GaAs protective layer 20 other than those covered with the photoresist pattern 16 are p-type. Etching is performed until the GaAs cap layer 9 is exposed.

Next, as shown in FIG. 18, after removing the photoresist pattern 16, the third crystal growth is performed to form the p-type GaAs contact layer 12 over the entire surface.
Thereafter, a p-type ohmic electrode 13 is formed on the p-type GaAs contact layer 12, and an n-type ohmic electrode 14 is formed on the n-type GaAs substrate 2 opposite to the stacking direction to obtain the semiconductor laser device 17 shown in FIG.
JP-A-9-199790

However, since the lower width of the p-type GaAs cap layer 9 is wider than the width of the p-type Al _x Ga _1-x As upper second cladding layer 7, the side surface of the ridge portion 8 is affected by the p-type GaAs cap layer 9. As a result, the crystal growth rate is reduced due to the oblique effect and the n-type Al _y Ga _1-y As current blocking layer 10 and the n-type GaAs protective layer 11 in the vicinity of the ridge portion 8 as shown in FIG. In some cases, voids 21 are generated in the p-type GaAs protective layer 20.
When this cavity 21 is generated, the refractive index distribution of the n-type Al _y Ga _1-y As current blocking layer 10 deviates from the design value, so that the waveguide characteristics fluctuate and the element characteristics vary. As a result, good laser characteristics cannot be obtained, causing a decrease in reliability. Further, since the heat conduction characteristics are lowered in the hollow portion, heat generated in the light emitting portion is not dissipated well, and there is a problem that the temperature characteristics are lowered.

  Therefore, the present invention has been proposed in view of the above-described problems, and prevents the generation of voids in the current blocking layer, and has a good laser characteristic and a highly reliable semiconductor laser element. It aims at providing the manufacturing method.

According to a first aspect of the present invention, a first conductivity type cladding layer, an active layer, a first second conductivity type cladding layer, and a second second conductivity type cladding layer are formed on a first conductivity type semiconductor substrate. And a second conductivity type cap layer are sequentially stacked, and further on the first second conductivity type cladding layer, sandwiching the ridge portion and the second conductivity type cap layer. In the semiconductor laser device having at least a first conductivity type current block layer, and a second conductivity type contact layer formed on the second conductivity type cap layer and the first conductivity type current block layer, the second conductivity type W ₁ width of the upper portion of the cap layer, W ₂ the widths of the lower portion of the second conductivity type cap layer, when the width of the upper of the ridge portion and W _3, the relationship of W _1> W ₂ = W ₃ A semiconductor laser device characterized by satisfying the requirements is provided.
According to a second aspect of the present invention, a first conductivity type lower cladding layer, an active layer, a first second conductivity type cladding layer, a second conductivity type etching stop layer, a second second conductivity type are formed on a first conductivity type semiconductor substrate. A conductive clad layer and a second conductive cap layer are sequentially stacked, and a striped photoresist pattern is formed in the [011] direction at the center of the second conductive cap layer, and then covered with the photoresist pattern. Etching is performed from the second conductivity type cap layer other than the second conductivity type cladding layer until reaching the second conductivity type etching stop layer to form the ridge portion, and then the photoresist pattern Then, a first conductivity type current blocking layer sandwiching the ridge portion and the second conductivity type cap layer is formed on the second conductivity type etching stop layer, and further, the second conductivity type In the method of manufacturing a semiconductor laser device, which is formed by forming a second conductivity type contact layer on the cap layer and the first conductivity type current blocking layer, the etching is performed by a dry etching method, and the second second conductivity type. A first step performed from the cap layer to the middle of the second second-conductivity-type cladding layer, and etching with a higher etching rate in the second second-conductivity-type cladding layer than in the second-conductivity-type etching stop layer Using a liquid, and performing the second second-conductivity-type cladding layer until reaching the second-conductivity-type etching stop layer and forming the second-conductivity-type cap layer in a reverse mesa shape. A method for manufacturing a semiconductor laser device is provided.

In the present invention, when the width of the upper part of the second conductivity type contact layer is W ₁ , the width of the lower part of the second conductivity type contact layer is W ₂ , and the width of the upper part of the ridge portion is W ₃ , W ₁ Since the structure satisfies the relationship> W ₂ = W ₃ , voids are prevented from occurring in the ridge portion, and a highly reliable semiconductor laser device can be obtained.
Further, the etching is performed by a dry etching method from a second stage of the second second conductivity type cap layer to the middle of the second second conductivity type cladding layer, and from the second conductivity type etching stop layer. The second second-conductivity-type cladding layer is etched until the second second-conductivity-type cladding layer reaches the second-conductivity-type etching stop layer using an etchant having a higher etching rate. Since the second conductivity type cap layer is formed in the second stage having an inverted mesa shape, the first conductivity type current without voids is not generated because the oblique effect by the second conductivity type cap layer does not occur as in the conventional example. A block layer can be obtained. As a result, a semiconductor laser device having good laser characteristics and high reliability and temperature characteristics can be obtained.

Hereinafter, embodiments of a semiconductor laser device and a method for manufacturing the same according to the present invention will be described in detail with reference to FIGS.
The same reference numerals are given to the same components as those in the prior art, and the description thereof is omitted.

FIG. 1 is a sectional view showing the configuration of a semiconductor laser device according to the present invention.
FIG. 2 is a cross-sectional view showing the (first stacking step) of the semiconductor laser device. FIG. 3 is a cross-sectional view showing the (first photoresist pattern forming step) of the semiconductor laser element. FIG. 4 is a cross-sectional view showing the (upper second cladding layer forming step) of the semiconductor laser device. FIG. 5 is a cross-sectional view showing the (ridge portion forming step) of the semiconductor laser device. FIG. 6 is a cross-sectional view showing the (double stacking step) of the semiconductor laser device. FIG. 7 is a cross-sectional view showing the (second photoresist pattern forming step) of the semiconductor laser device. FIG. 8 is a sectional view showing the (etching process) of the semiconductor laser device. FIG. 9 is a cross-sectional view showing the (contact layer forming step) of the semiconductor laser device.

As shown in FIG. 1, in the semiconductor laser device 1 according to the present invention, the width of the upper portion of the p-type GaAs cap layer 9 in the conventional semiconductor laser device 17 is W ₁ and the width of the lower portion of the p-type GaAs cap layer 9 is W. ₂ , where the width of the upper portion of the ridge portion 8 is W ₃ , the configuration satisfies the relationship of W ₁ > W ₂ = W ₃ , and the rest is the same.

This will be specifically described below.
The semiconductor laser device 1 according to the embodiment of the present invention is formed on an n-type GaAs substrate 2 having a thickness of 50 μm to 130 μm and an n-type Al _t Ga _1-t As (0.45 ≦ t ≦ 0.5 μm to 2 μm). 0.65) Lower cladding layer 3, 0.01 μm to 0.1 μm Al _u Ga _1-u As (0.07 ≦ u ≦ 0.65) active layer 4, p having a thickness of 0.1 μm to 0.4 μm Type Al _v Ga _1-v As (0.45 ≦ v ≦ 0.65) upper first cladding layer 5, p-type Al _w Ga _1-w As (0.5 ≦ 0.5) having a thickness of 0.002 μm to 0.02 μm w ≦ 0.8) Etching stop layers 6 are sequentially stacked.

Further, on the p-type Al _w Ga _1-w As etching stop layer 6, an upper part of p-type Al _x Ga _1-x As (0.45 ≦ x ≦ 0.65) having a thickness of 0.3 μm to 2.5 μm. A rectangular ridge portion 8 made of the second cladding layer 7 is formed. On the ridge portion 8, a p-type GaAs cap layer 9 having a reverse mesa shape thickness of 0.2 μm to 1.0 μm having the same width as the upper portion of the ridge portion 8 is formed.

When the upper width of the p-type GaAs cap layer 9 is W ₁ , the lower width of the p-type GaAs cap layer 9 is W ₂ , and the upper width of the ridge portion 8 is W ₃ , W ₁ > W ₂ = W ₃ Have the relationship.

Further, on the p-type Al _w Ga _1-w As etching stop layer 6, the side surface of the ridge portion 8 and the p-type GaAs cap layer 9 is sandwiched so as to have an n-type thickness of 0.2 μm to 1.0 μm. An Al _y Ga _1-y As (0.5 ≦ y ≦ 0.85) current blocking layer 10 and an n-type GaAs protective layer 11 having a thickness of 0.2 μm to 1.0 μm are sequentially formed.

Furthermore, a p-type GaAs contact layer 12 having a thickness of 1 to 10 μm is formed on the n-type GaAs protective layer 11 and the p-type GaAs cap layer 9.
A p-type ohmic electrode 13 is formed on the p-type GaAs contact layer 12, and an n-type ohmic electrode 14 is formed on the n-type GaAs substrate 2 opposite to the stacking direction.
The semiconductor laser element 1 emits laser light from the Al _u Ga _1-u As active layer 4 by injecting a current from the p-type ohmic electrode 13 side toward the n-type ohmic electrode side.

Thus, when the width of the upper portion of the p-type GaAs contact layer 12 is W ₁ , the width of the lower portion of the p-type GaAs contact layer 12 is W ₂ , and the width of the upper portion of the ridge portion 8 is W ₃ , W ₁ > W ₂ = W ₃ is satisfied, so that the current is confined in the n-type Al _y Ga _{1 -y} As current blocking layer 10 without causing a reactive current, and an effective current flows through the ridge 8. Therefore, a semiconductor laser device having good laser characteristics can be obtained.

Next, a method for manufacturing a semiconductor laser device according to the present invention will be described with reference to FIGS. In the following, crystal growth is performed by MOCVD (Metal Organic Chemical Vapor Deposition).
(First lamination process)
As shown in FIG. 2, the first crystal growth is performed to form an n-type Al _t Ga _1-t As lower cladding layer 3, an Al _u Ga _1-u As active layer 4, p on the n-type GaAs substrate 2. Type Al _v Ga _{1 -v} As upper cladding layer 5, p type Al _w Ga _{1 -w} As etching stop layer 6, p type Al _x Ga _{1 -x} As upper second cladding layer 7, and p type GaAs cap layer 9 Laminate sequentially.

(First photoresist pattern formation process)
Next, as shown in FIG. 3, a striped photoresist pattern 15 is formed in the [011] direction on the p-type GaAs cap layer 9 by photolithography.

(Upper second cladding layer forming step)
Next, as shown in FIG. 4, the p-type GaAs cap layer 9 to the p-type Al _x Ga _1-x As upper second cladding layer 7 in the region not covered with the photoresist pattern 15 is etched partway. Here, as this etching method, ICP-RIE (inductive coupling) is possible in which anisotropic etching can be performed on AlGaAs and GaAs, and the side surfaces of these layers can be etched perpendicular to the n-type GaAs substrate 2 surface. Plasma reactive ion etching) was used. The etching amount can be controlled by using an etching monitor or by time control.

(Ridge formation process)
Next, as shown in FIG. 5, the p-type Al _x Ga _1-x As upper second cladding layer 7 is further etched until it reaches the p-type Al _w Ga _1-w As etching stop layer 6. A ridge portion 8 having a shape is formed. As the etching solution used at this time, a tartaric acid-based etchant having an etching rate faster than that of the p-type Al _x Ga _1-x As upper second cladding layer 7 than the p-type Al _w Ga _1-w As etching stop layer 6 is used. Further, by controlling the etching time, the upper width of the p-type GaAs cap layer 9 can be made wider than the lower width. The crystal orientation of the side surface of the p-type GaAs cap layer 9 is the (111) plane.

That is, since this etchant has anisotropy in the etching rate with respect to the GaAs crystal orientation, the angle formed between the side surface and the bottom surface of the p-type GaAs cap layer 9 becomes 90 ° or more, and a so-called inverted mesa shape is formed. When the upper width of the p-type GaAs cap layer 9 is W ₁ , the lower width of the p-type GaAs cap layer 9 is W ₂ , and the upper width of the ridge 8 is W ₃ , W ₁ > W ₂ = W ₃ relationship.

In addition, the p-type Al _w Ga _1-w As etching stop layer 6 can have a sufficient etching selectivity with respect to the p-type Al _x Ga _1-x As upper second cladding layer 7 and Al _u Ga _{1- The} composition is selected so that the laser light emitted from the _u As active layer 4 can be transmitted.

(2 times lamination process)
Next, as shown in FIG. 6, after removing the photoresist pattern 15, the second crystal growth is performed to form the n-type Al _y Ga _1-y As current blocking layer 10 and the n-type GaAs protective layer 11. Laminate sequentially.

(Second photoresist pattern formation process)
Next, as shown in FIG. 7, a photoresist pattern 16 having a central portion opened on the n-type Al _y Ga _1-y As current blocking layer 10 and the n-type GaAs protective layer 11 stacked on the ridge portion 8 is formed. Form.

(Etching process)
Next, as shown in FIG. 8, the p-type GaAs cap layer 9 exposes the n-type Al _y Ga _1-y As current blocking layer 10 and the n-type GaAs protective layer 11 other than those covered with the photoresist pattern 16. Etch until.

(Contact layer formation process)
Next, as shown in FIG. 9, after removing the photoresist pattern 16, the third crystal growth is performed to form the p-type GaAs contact layer 12 over the entire surface.
Thereafter, the p-type ohmic electrode 13 is formed on the p-type GaAs contact layer 12, and the n-type ohmic electrode is formed on the n-type GaAs substrate 14 on the side opposite to the stacking direction, thereby obtaining the semiconductor laser device 1 shown in FIG.

As described above, the striped photoresist pattern 15 is formed in the [011] direction at the center of the p-type GaAs cap layer 9 and the p-type GaAs cap layers 9 to p other than those covered with the photoresist pattern 15 are formed. perform the type Al _x Ga _1-x As upper inductively coupled plasma reactive ion etching until the middle of the second cladding layer 7, the vertical their sides against n-type GaAs substrate 2 side, further using a tartaric acid system etchant Then, the p-type Al _x Ga _1-x As upper second cladding layer 7 is etched until it reaches the p-type Al _w Ga _1-w As etching stop layer 6, and the ridge portion 8 and the reverse mesa-shaped p-type GaAs. After the cap layer 9 is formed, the ridge 8 and the inverted mesa-shaped p-type GaAs cap layer 9 are sandwiched between the p-type Al _w Ga _1-w As etching stop layer 6 and n Since the n _- type Al _y Ga _1-y As current blocking layer 10 and the n-type GaAs protective layer 11 are sequentially stacked, the oblique effect due to the p-type GaAs cap layer 9 does not occur as in the conventional example, so that no voids are generated. The n-type Al _y Ga _1-y As current blocking layer 10 and the n-type GaAs protective layer 11 can be obtained. As a result, it is possible to obtain a semiconductor laser device 1 having good laser characteristics and high reliability and temperature characteristics.

A second n-type GaAs buffer layer or a n-type GaAs protective layer 11 and a p-type GaAs contact layer 12 are provided between the n-type GaAs substrate 2 and the n-type Al _t Ga _1-t As lower cladding layer 3. A p-type GaAs layer may be provided as a protective layer. Other dry etching methods may be used instead of inductively coupled plasma reactive ion etching.
In the embodiment, the AlGaAs-based semiconductor laser element has been described. Needless to say, the present invention can be applied to an InGaAlP-based semiconductor laser or a semiconductor laser element having a ridge portion similar to this.

It is sectional drawing which shows the structure of the semiconductor laser element concerning this invention. It is sectional drawing which shows (the 1st lamination process) of a semiconductor laser element. It is sectional drawing which shows (the 1st photo resist pattern formation process) of a semiconductor laser element. It is sectional drawing which shows (upper 2nd clad layer formation process) of a semiconductor laser element. It is sectional drawing which shows (ridge part formation process) of a semiconductor laser element. It is sectional drawing which shows (two times lamination process) of a semiconductor laser element. It is sectional drawing which shows (2nd photoresist pattern formation process) of a semiconductor laser element. It is sectional drawing which shows the (etching process) of a semiconductor laser element. It is sectional drawing which shows (contact layer formation process) of a semiconductor laser element. It is sectional drawing which shows the structure of the conventional semiconductor laser element. It is sectional drawing which shows the 1st lamination process of the conventional semiconductor laser element. It is sectional drawing which shows the 1st photoresist pattern formation process of the conventional semiconductor laser element. It is sectional drawing which shows the upper 2nd clad layer formation process of the conventional semiconductor laser element. It is sectional drawing which shows the ridge part formation process of the conventional semiconductor laser element. It is sectional drawing which shows the 2nd lamination process of the conventional semiconductor laser element. It is sectional drawing which shows the 2nd photoresist pattern formation process of the conventional semiconductor laser element. It is sectional drawing which shows the etching process of the conventional semiconductor laser element. It is sectional drawing which shows the contact layer process of the conventional semiconductor laser element. It is a figure explaining the problem of the conventional semiconductor laser element.

Explanation of symbols

1 ... semiconductor laser, 2 ... n-type GaAs substrate (first conductivity type semiconductor substrate), 3 ... n-type Al _t Ga _1-t As lower clad layer (first conductivity type cladding layer), 4 ... Al _u Ga _{1 -u} As active layer (active layer), 5 ... p-type Al _v Ga _1-v As upper first cladding layer (first second conductivity type clad layer), 6 ... p-type Al _w Ga _1-w As etching Stop layer (second conductivity type etching stop layer), 7... P-type Al _x Ga _1-x As upper second cladding layer (second second conductivity type cladding layer), 8... Ridge portion, 9. Cap layer (second conductivity type cap layer), 10... N-type Al _y Ga _1-y As current blocking layer (first conductivity type current blocking layer), 11... N-type GaAs protective layer, 12. (Second conductivity type contact layer), 13 ... p-type ohmic electrode, 14 ... n-type ohmic Click the electrode, 15, 16 ... photoresist pattern

Claims (2)

A ridge portion comprising a first conductivity type cladding layer, an active layer, a first second conductivity type cladding layer, and a second second conductivity type cladding layer on a first conductivity type semiconductor substrate; A first conductivity type current blocking layer sandwiching the ridge portion and the second conductivity type cap layer on the first second conductivity type cladding layer; In the semiconductor laser device having at least a second conductivity type contact layer formed on the second conductivity type cap layer and the first conductivity type current blocking layer,
When the upper width of the second conductivity type cap layer is W ₁ , the lower width of the second conductivity type cap layer is W ₂ , and the upper width of the ridge portion is W ₃ , W ₁ > W ₂ = A semiconductor laser device satisfying the relationship of W ₃ . A first conductivity type lower cladding layer, an active layer, a first second conductivity type cladding layer, a second conductivity type etching stop layer, a second second conductivity type cladding layer, a first conductivity type lower cladding layer, an active layer, A two-conductivity type cap layer is sequentially stacked, a stripe-shaped photoresist pattern is formed in the [011] direction at the center of the second conductivity-type cap layer, and then the second conductive layer is covered with the photoresist pattern. Etching the second second conductivity type cladding layer from the conductivity type cap layer until it reaches the second conductivity type etching stop layer to form a ridge portion, and then removing the photoresist pattern, Forming a first conductivity type current blocking layer sandwiching the ridge portion and the second conductivity type cap layer on the two conductivity type etching stop layer; and further, the second conductivity type cap layer and The method of manufacturing a semiconductor laser device produced by forming a second conductivity type contact layer in serial first conductivity type current blocking layer,
The etching is performed by a dry etching method from the second second conductivity type cap layer to the middle of the second second conductivity type cladding layer, and more than the second conductivity type etching stop layer. The second second conductivity type cladding layer is etched using an etchant having a higher etching rate until the second second conductivity type cladding layer reaches the second conductivity type etching stop layer, and the second A method of manufacturing a semiconductor laser device, comprising: a second step in which the conductive cap layer has an inverted mesa shape.

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