JP2008182177A - Semiconductor laser element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a high-reliability semiconductor laser element, in which a kink level is improved by cutting of a primary transverse mode without making the ridge width narrow. <P>SOLUTION: The semiconductor laser element is provided with a first ridge 12 constituted of a p-type AlGaInP clad layer 8 formed on a p-type AlGaInP clad layer 6 in a first region S1 when an n-type semiconductor substrate 2 between both cleavage surfaces is divided into a first region S1 and a second region S2, and a p-type AlGaInP clad layer 10; a second ridge 13, comprising a p-type AlGaInP clad layer 8 formed on the p-type AlGaInP clad layer 6 in the second region S2 and the p-type AlGaInP clad layer 10 formed on the p-type AlGaInP clad layer 8; and a pair of AlInP current narrowing layers 14 for holding the ridges 12, 13 formed on the p-type AlGaInP clad layers 6, 8. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a semiconductor laser element used for a light source such as optical information processing and optical measurement, and relates to a semiconductor laser element using, for example, an AlGaInP-based material.

In general, a semiconductor laser element using an AlGaInP-based material is widely used as a light source for a high-density disk device, a laser printer light source, a bar code reader, and optical measurement (Patent Document 1, etc.).
The conventional semiconductor laser device will be described below with reference to FIGS.
FIG. 5 is a perspective view showing an example of a conventional semiconductor laser device, and FIG. 6 is a sectional view thereof. Here, the first conductivity type is n-type, and the second conductivity type is p-type.

As shown in FIGS. 5 and 6, the conventional semiconductor laser element has an n-type GaAs (semiconductor) substrate 2 of the first conductivity type, for example, and an Au-based second layer is formed on one surface of the substrate 2. An n-type ohmic electrode 1 as an electrode is formed. And on the opposite side of the substrate 2, 1 × 10 ¹⁸ cm and n-type GaAs buffer layer 3 doped with Si of ^-3, 1 × 10 ¹⁸ doped with Si of cm ^-3 n-type (Al _0.7 Ga _{0.3) 0.5} In _0.5 P cladding layer 4, active layer 5 made of non-doped MQW (multiple quantum well layer) (hereinafter also simply referred to as “active layer”), first doped with 5 × 10 ¹⁷ cm ⁻³ Zn A p-type (Al _0.7 Ga _0.3 ) _0.5 In _0.5 P cladding layer 6 and a p-type In _0.5 Ga _0.5 P etching stop layer 7 doped with 1 × 10 ¹⁸ cm ⁻³ Zn are sequentially stacked.

The active layer 5 has, for example, a double quantum well structure and includes a non-doped Ga _0.5 In _0.5 P well layer and a non-doped (Al _0.3 Ga _0.7 ) _0.5 In _0.5 P barrier layer. The n-type (Al _0.7 Ga _0.3 ) _0.5 In _0.5 P clad layer 4, the active layer 5, and the first p-type (Al _0.7 Ga _0.3 ) _0.5 In _0.5 P clad layer 6 form a double heterostructure. is doing.

Further, on the p-type Ga _0.5 In _0.5 P etching stop layer 7, a second p-type (Al _0.7 Ga _0.3 ) _0.5 In _0.5 P cladding layer 8 doped with 1 × 10 ¹⁸ cm ⁻³ Zn, and 2 A ridge 20 is formed, in which a p-type In _0.5 Ga _0.5 P cap layer 9 doped with × 10 ¹⁸ cm ⁻³ Zn is sequentially laminated. The cross-sectional shape of the ridge 20 is a trapezoidal shape in which the length of the upper side is shorter than the length of the lower side.

Furthermore, a pair of n-type Al _0.5 In doped with 1 × 10 ¹⁸ cm ⁻³ Si so as to sandwich the ridge 20 formed on the p-type Ga _0.5 In _0.5 P etching stop layer 7 from both sides thereof. _{A 0.5} P current confinement layer 14 is formed. A p-type GaAs contact layer 15 doped with 2 × 10 ¹⁸ cm ⁻³ Zn is laminated on the ridge 20 and the pair of n-type Al _0.5 In _0.5 P current confinement layers 14.

An Au-based p-type ohmic electrode 16 is formed on the p-type GaAs contact layer 15, and the Au-based n-type ohmic electrode 1 is formed on the n-type GaAs substrate 2 opposite to the stacking direction as described above. Is formed.
Here, the p-type Ga _0.5 In _0.5 P etching stop layer 7 is provided to stop the etching and obtain the ridge 20 having a fixed shape. The p-type Ga _0.5 In _0.5 P etching stop layer 7 needs to be as thin as possible in order to suppress absorption loss with respect to laser light, and the film thickness is about 3 nm.

A semiconductor wafer having such an internal structure is cleaved with a predetermined length in a direction perpendicular to the ridge 20, and an actual refractive index type semiconductor laser device is manufactured using both end faces as mirrors. That is, the both end surfaces are resonator surfaces. Here, the width of the ridge 20, that is, the ridge width H <b> 1 has the same dimension along the longitudinal direction.
This semiconductor laser device injects a current in the forward direction from the p-type ohmic electrode 16 side to the n-type ohmic electrode 1 side, and corresponds to the lower portion of the ridge 20 when this current exceeds the oscillation threshold value. Laser light is emitted from the active layer 5 by laser oscillation.
Japanese Patent Laid-Open No. 5-299863

By the way, in the above-described conventional real refractive index type semiconductor laser device, since the difference in waveguide loss between the zeroth-order transverse mode and the first-order transverse mode is small, the kink level (the level at which the first-order mode oscillates) becomes small and the operation There is a problem that the linear increase of the optical output cannot be maintained with respect to the current.
In this case, as a general method for improving the kink level, it is conceivable to narrow the ridge width H1 so that only the 0th-order transverse mode propagates. This method is applied to a real refractive index type semiconductor laser device. Then, the ridge width becomes extremely narrow, and there is a problem that the reliability of the element is remarkably deteriorated due to heat generation due to an increase in resistance of the ridge portion, and this method cannot be applied.

  Further, as another means for solving the problem, for example, as shown in FIG. 7, the kink level can be improved by making the width L1 of the current flowing portion 21 on the upper surface side of the ridge 20 smaller than the ridge width H1. (See Patent Document 1). However, if the current flowing portion 21 is narrowed in order to sufficiently obtain the above effect, the current density in the ridge 20 increases, and in this case, the reliability is deteriorated due to heat generation, so that a sufficient effect cannot be expected. there were.

  Therefore, the present invention solves the above-mentioned problems, cuts off the primary transverse mode without reducing the width of the ridge through which the current flows, improves the kink level, and is reliable. An object is to provide a high semiconductor laser element.

In the present invention, when the gap between the two cleavage surfaces of the first conductivity type semiconductor substrate is divided into the first region and the second region, the first and second regions are sequentially stacked on the semiconductor substrate. A first conductivity type AlGaInP clad layer, an active layer, a first second conductivity type AlGaInP clad layer, and a first second conductivity type AlGaInP clad layer in the first region in the direction of the cleavage plane. A first ridge formed of a second second-conductivity-type AlGaInP clad layer and a third second-conductivity-type AlGaInP clad layer formed in a stripe shape, and a first first ridge in the second region. A second second-conductivity-type AlGaInP clad layer formed on the two-conductivity-type AlGaInP clad layer, and a second-conductivity-type AlGaInP clad layer on the second cleavage-type AlGaInP clad layer along the cleavage plane direction. A second ridge made of the third second-conductivity-type AlGaInP clad layer formed in the shape of a plug, and the first and second ridges formed on the first and second second-conductivity-type AlGaInP clad layers. A pair of first conductivity type AlInP current confinement layers sandwiching two ridges, and a second conductivity type GaAs formed on the first and second ridges and the pair of first conductivity type AlInP current confinement layers A semiconductor laser device comprising: a contact layer.
According to a second aspect of the present invention, when the space between the two cleaved surfaces of the first conductivity type semiconductor substrate is divided into a first region to a third region, the first region to the third region are sequentially formed on the semiconductor substrate. The first conductivity type AlGaInP clad layer, the active layer, the first second conductivity type AlGaInP clad layer, and the first second conductivity type AlGaInP clad layer in the first region. A first ridge formed of a second second-conductivity-type AlGaInP clad layer and a third second-conductivity-type AlGaInP clad layer formed in a stripe shape along the both cleavage planes; A second second-conductivity-type AlGaInP clad layer formed on the first second-conductivity-type AlGaInP clad layer in the second region, and in the second region, the second second-type Conductive AlGaIn The AlGaInP clad layer of the third second conductivity type formed in a stripe shape along the cleaved surface direction on the clad layer, connected to the first ridge, and from the first region A second ridge formed by continuously reducing the width of the first ridge toward the third region, and the second ridge of the second second conductivity type in the third region. The AlGaInP clad layer is composed of the third second conductivity type AlGaInP clad layer formed in a stripe shape along the both cleavage planes, and is connected to the second ridge, A third ridge having the same width and a pair of AlInP current confinement layers of the first conductivity type sandwiching the first to third ridges formed on the first and second conductivity type AlGaInP cladding layers. And the first to third re- To provide a semiconductor laser device characterized by comprising a second conductivity type GaAs contact layer formed on di- and said pair of first conductive type AlInP current constriction layer, the.
According to a third aspect of the present invention, the first region is a region surrounded by a surface orthogonal to the semiconductor substrate and the cleavage surface at a position separated by 30 μm or more from either one of the cleavage surfaces. A semiconductor laser device according to claim 1 or 2 is provided.

According to the present invention, the second second-conductivity-type AlGaInP clad layer formed in stripes along the both cleavage planes on the first second-conductivity-type AlGaInP clad layer in the first region and the second A first ridge composed of three second-conductivity-type AlGaInP clad layers, and a second second-conductivity-type AlGaInP clad formed on the first second-conductivity-type AlGaInP clad layer in the second region A second ridge composed of a third second conductivity type AlGaInP clad layer formed in a stripe shape along the cleavage plane on the second second conductivity type AlGaInP clad layer; 1 and a pair of AlInP current confinement layers sandwiching the first and second ridges formed on the second second conductivity type AlGaInP clad layer. Without narrowing the width, cut off the primary lateral mode, thereby improving the kink level, and can provide a highly reliable semiconductor laser device.
A second second conductivity type AlGaInP cladding layer formed in a stripe shape in the first region and formed on the first second conductivity type AlGaInP cladding layer along the cleavage plane direction. A first ridge composed of three second-conductivity-type AlGaInP clad layers, and a second second-conductivity-type AlGaInP clad formed on the first second-conductivity-type AlGaInP clad layer in the second region And a third second-conductivity-type AlGaInP clad layer that is formed in a stripe shape in the second region and on the second second-conductivity-type AlGaInP clad layer along both cleavage planes A second ridge connected to the first ridge and formed by continuously reducing the width of the first ridge from the first region toward the third region; In the territory and the second The second conductivity type AlGaInP clad layer is formed of a third second conductivity type AlGaInP clad layer formed in a stripe shape along both cleavage planes on the two conductivity type AlGaInP clad layer, and is connected to the second ridge, The same effect can be obtained when the third ridge having the same width is provided.

Hereinafter, an example of a semiconductor laser device according to an embodiment of the present invention will be described with reference to the accompanying drawings.
1 is a perspective view showing a semiconductor laser device according to an embodiment of the present invention, FIG. 2 is a cross-sectional view showing the semiconductor laser device in FIG. 1, and FIG. 2 (A) is a line AA in FIG. An arrow sectional view and FIG. 2 (B) are BB arrow sectional drawings in FIG. In addition, the same code | symbol is attached | subjected to the structure same as the conventional element shown in FIGS.

The semiconductor laser device LA according to the embodiment of the present invention includes an n-type ohmic electrode that is an Au (gold) -based second electrode on an n-type GaAs (gallium arsenide) substrate 2 having a pair of cleavage planes 2A and 2B. 1 The opposite side of the n-type GaAs substrate 2 is an n-type GaAs buffer layer 3 doped with 1 × 10 ¹⁸ cm ⁻³ Si (silicon) and an n-type doped with 1 × 10 ¹⁸ cm ⁻³ Si. (Al _0.7 Ga _0.3 ) _0.5 In _0.5 P (aluminum gallium indium phosphide) cladding layer 4, active layer 5 made of non-doped MQW (multiple quantum well layer) (hereinafter also simply referred to as “active layer”), 5 × 10 First p-type (Al _0.7 Ga _0.3 ) _0.5 In _0.5 P clad layer 6 doped with ¹⁷ cm ⁻³ Zn and first p-type Ga doped with 1 × 10 ¹⁸ cm ⁻³ Zn (zinc) _{A 0.5} In _0.5 P (gallium indium phosphide) etching stop layer 7 is sequentially stacked.

The active layer 5 has, for example, a double quantum well structure and includes a non-doped Ga _0.5 In _0.5 P well layer and a non-doped (Al _0.3 Ga _0.7 ) _0.5 In _0.5 P barrier layer. The n-type (Al _0.7 Ga _0.3 ) _0.5 In _0.5 P clad layer 4, the active layer 5, and the first p-type (Al _0.7 Ga _0.3 ) _0.5 In _0.5 P clad layer 6 form a double heterostructure. is doing.

Further, a surface perpendicular to the n-type GaAs substrate 2 and the cleavage surface 2A along the direction connecting the pair of cleavage surfaces 2A and 2B of the n-type GaAs substrate 2 and at a predetermined length (side 2C) from the cleavage surface 2A. On the first p-type Ga _0.5 In _0.5 P etching stop layer 7 in the first region S 1 surrounded by the second p-type (Al _0.7 Ga _0.3) doped with 1 × 10 ¹⁸ cm ⁻³ Zn. ) _0.5 In _0.5 P cladding layer 8, second p-type Ga _0.5 In _0.5 P etching stop layer 9 doped with 1 × 10 ¹⁸ cm ⁻³ Zn (zinc), and 1 × 10 ¹⁸ cm ⁻³ Zn A third p-type (Al _0.7 Ga _0.3 ) _0.5 In _0.5 P cladding layer 10 doped with (zinc) and a p-type In _0.5 Ga _0.5 P cap layer 11 doped with 1 × 10 ¹⁸ cm ⁻³ Zn A ridge 12 that is sequentially laminated has a pair of cleavage planes 2A, 2B is formed in a stripe shape in the direction connecting 2B (FIG. 2A).

The first region in the second region S2 is surrounded by a side 2C having a predetermined length from the cleavage plane 2A and the cleavage plane 2B along the direction connecting the pair of cleavage planes 2A and 2B of the n-type GaAs substrate 2. On the p-type Ga _0.5 In _0.5 P etching stop layer 7, a second p-type (Al _0.7 Ga _0.3 ) _0.5 In _0.5 P cladding layer 8 and a second p-type Ga _0.5 In _0.5 P etching stop layer 9 are formed. Are sequentially stacked.
On the second p-type Ga _0.5 In _0.5 P etching stop layer 9, a third p-type (Al _0.7 Ga _0.3 ) _0.5 In _0.5 doped with 1 × 10 ¹⁸ cm ⁻³ Zn (zinc) is formed. A ridge 13 in which a P-clad layer 10 and a p-type In _0.5 Ga _0.5 P cap layer 11 doped with 1 × 10 ¹⁸ cm ⁻³ Zn are sequentially stacked in a stripe shape in a direction connecting the cleavage planes 2A and 2B. It is formed (FIG. 2B). The cross-sectional shape of the ridges 12 and 13 has a trapezoidal shape in which the length of the upper side is shorter than the length of the lower side.

Furthermore, 1 × 10 ¹⁸ cm sandwiching the ridges 12 and 13 formed on the first p-type Ga _0.5 In _0.5 P etching stop layer 7 and the second p-type Ga _0.5 In _0.5 P etching stop layer 9, respectively. A pair of n-type Al _0.5 In _0.5 P (aluminum indium phosphide) current confinement layers 14 doped with ⁻³ Si is formed. A p-type GaAs contact layer 15 doped with 2 × 10 ¹⁹ cm ⁻³ Zn is laminated on the ridges 12 and 13 and the pair of n-type Al _0.5 In _0.5 P current confinement layers 14.

An Au-based p-type ohmic electrode 16 is formed on the p-type GaAs contact layer 15, and the Au-based n-type ohmic electrode 1 is formed on the n-type GaAs substrate 2 opposite to the stacking direction as described above. As a whole, the resonator structure 17 is formed.
Here, the cleavage plane 2A is on the emission end face side that emits laser light. The first and second p-type Ga _0.5 In _0.5 P etching stop layers 7 and 9 are provided to stop etching and obtain ridges 12 and 13 having a fixed shape. The p-type Ga _0.5 In _0.5 P etching stop layers 7 and 9 need to be made as thin as possible in order to suppress absorption loss with respect to laser light, and the film thickness is about 3 nm.

Next, the fact that the primary transverse mode can be cut off without reducing the width of the ridges 12 and 13 will be described based on the concept of the equivalent refractive index method.
Here, the first p-type (Al _0.7 Ga _0.3 ) _0.5 In _0.5 P cladding layer 6 and the first p-type Ga laminated on the ridge portion 12 and the n-type Al _0.5 In _0.5 P current confinement layer 14. The first and second cross-sectional areas formed by the _0.5 In _0.5 P etching stop layer 7 are defined as first and second cross-sectional areas, respectively, and are stacked below the ridge 13 and the n-type Al _0.5 In _0.5 P current confinement layer 14. The cross-sectional regions from the p-type (Al _0.7 Ga _0.3 ) _0.5 In _0.5 P cladding layer 6 to the second p-type Ga _0.5 In _0.5 PP etching stop layer 9 are defined as third and fourth cross-sectional regions, respectively. Further, when the equivalent refractive index in the first and third sectional regions is n1, the equivalent refractive index in the second sectional region is n2, and the equivalent refractive index in the fourth sectional region is n3, the equivalent refractive indexes n1 to n3 There is a relationship of n1>n3> n2 between them.

This relationship can be explained as follows.
The reason why n1> n3 is satisfied is that the second p-type (Al _0.7 Ga _0.3 ) _0.5 In _0.5 P cladding layer 8 and the third p-type (Al _0.7 Ga _0.3 ) _0.5 In _0.5 P cladding layer 10 are n-type Al. _0.5 in _0.5 the refractive index than the P current region 14 is large, the ridge 13 is the refractive index than the n-type Al _0.5 in _0.5 P current region 14 is increased.

The p-type cladding layer formed under the ridge 13 includes a first p-type (Al _0.7 Ga _0.3 ) _0.5 In _0.5 P cladding layer 6 and a second p-type (Al _0.7 Ga _0.3 ) _0.5 In. while consisting _0.5 P cladding layer 8 Prefecture, p-type cladding layer formed on the lower portion of the ridge 12, since the first p-type _{(Al 0.7 Ga 0.3) 0.5 in} 0.5 P cladding layer 6, the ridge 13 The p-type cladding layer formed in the lower part is formed thicker by the second p-type (Al _0.7 Ga _0.3 ) _0.5 In _0.5 P cladding layer 8.
Further, the refractive index of the ridge 13 is determined only by the third p-type (Al _0.7 Ga _0.3 ) _0.5 In _0.5 P cladding layer 10, whereas the p-type cladding layer formed below the ridge 13. Is the sum of the p-type (Al _0.7 Ga _0.3 ) _0.5 In _0.5 P cladding layer 6 and the second p-type (Al _0.7 Ga _0.3 ) _0.5 In _0.5 P cladding layer 8. Since the refractive index of the p-type cladding layer formed in the above is larger than the refractive index of the ridge 13 and becomes dominant, n3> n2.

Because of this relationship, the refractive index difference between the refractive index n1 of the third cross-sectional area and the refractive index n3 of the fourth cross-sectional area in the second region S2 where the ridge 13 is formed is the same as that of the ridge 12 The first transverse mode is cut off without reducing the width of the ridge 13 because the difference in refractive index between the refractive index n1 of the first sectional region and the refractive index n2 of the second sectional region in the first region S1 is smaller. be able to. For this reason, in the second region S2 where the ridge 13 is formed, the primary transverse mode does not propagate, so that the waveguide loss of the primary transverse mode is increased and the oscillation of the primary transverse mode is suppressed. . As a result, the waveguide loss difference between the zeroth-order transverse mode and the first-order transverse mode can be increased, and the kink level at which the first-order transverse mode oscillates can be improved.
However, if the difference in refractive index is small, the zeroth-order transverse mode also spreads laterally, so that the far field pattern of laser light emitted from the end face becomes too narrow.

In order to prevent this, in the first region S1 in the vicinity of the end face from which the laser beam is emitted, the p-cladding layer in the second cross-sectional region is made to be the first p-type (Al _0.7 Ga _0.3) in order to increase the refractive index difference. ) Only _0.5 In _0.5 P cladding layer 6 is used.
Further, the length 2C of the first region S1 needs to be 30 μm or more in order to obtain a far field pattern having a predetermined shape. This length is provided so that the high-order transverse mode component in the second region S2 of the laser light propagated through the first region S1 is sufficiently attenuated, and the laser light emitted from the emission end face produces a good far field pattern. It is what was done.
In this structure, since the width of the ridges 12 and 13 is not reduced, heat generation in this portion can be suppressed, and the reliability of the semiconductor laser element can be improved.

Here, since the operating current-light output characteristics of the semiconductor laser device according to the present invention and the conventional semiconductor laser device were actually measured and evaluated, the evaluation results will be described. FIG. 3 is a graph showing operating current-light output characteristics of the semiconductor laser device according to the present invention and the conventional semiconductor laser device. As shown in FIG. 3, in the conventional semiconductor laser element, the operating current and the optical output do not change linearly, and kinks are generated at a relatively low optical output.
In contrast, in the semiconductor laser device of the present invention, the operating current and the optical output change linearly, and it was confirmed that no kink occurred.

As described above, according to the embodiment of the present invention, the p-cladding layer formed below the ridge 12 in the first region S1 is configured by the p-type (Al _0.7 Ga _0.3 ) _0.5 In _0.5 P-cladding layer 6. The p-cladding layer formed below the ridge 13 in the second region S2 is composed of the first p-type (Al _0.7 Ga _0.3 ) _0.5 In _0.5 P clad layer 6 and the second p-type (Al _0.7 Ga _0.3 ) _0.5 In _Since it has a relationship of n1>n3> n2 between the effective refractive indexes n1, n2, and n3, the primary transverse mode can be cut off, and the kink level can be reduced. Can be improved. In addition, since the width of the ridges 12 and 13 through which the current flows is not reduced, heat generation due to the current can be prevented, so that a highly reliable semiconductor laser device can be provided.

Next, another embodiment of the present invention will be described with reference to FIG.
The same components as those of the embodiment are denoted by the same reference numerals, and the description thereof is omitted.
As shown in FIG. 4, the semiconductor laser device according to another embodiment includes two regions S3 in the second region S2 in the semiconductor laser device LA according to the embodiment along the direction connecting the pair of cleavage surfaces 2A and 2B. , S4, which is in one of the regions S3, is connected to the ridge 12 from the first region S1 toward the other region S4, and the width of the ridge 12 is continuously narrowed. 18 is different from the semiconductor laser device LA according to the embodiment except that it includes a ridge 19 in the other region S4 and connected with the same width as the ridge 18.

Specifically, the width of the ridge 18 in the region S3 continuously changes from 4 μm to 3.5 μm, and the width of the ridge 19 in the region S4 is 3.5 μm.
The length M of the region S3 may be about 30 μm.
As described above, effects similar to those of the semiconductor laser device LA of the embodiment can be obtained in the other embodiments.

Note that the cross-sectional structure of the region S3 may be the same as that of the first region S1 and the region S4.
The first region S1 may be formed on either end face side of the resonator structure 17.
Furthermore, the same effect can be obtained even if the conductivity type of each layer is set in reverse.

1 is a perspective view showing a semiconductor laser device according to an embodiment of the present invention. It is sectional drawing which shows the semiconductor laser element in FIG. It is a graph which shows the operating current-light output characteristic of the semiconductor laser element which concerns on this invention, and the conventional semiconductor laser element. It is a perspective view which shows the semiconductor laser element which concerns on other embodiment of this invention. It is a perspective view which shows an example of the conventional semiconductor laser element. It is sectional drawing which shows an example of the conventional semiconductor laser element. It is sectional drawing which shows another example of the conventional semiconductor laser element.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... n-type ohmic electrode (2nd electrode), 2 ... n-type GaAs substrate (1st conductivity type semiconductor substrate), 2A, 2B ... cleavage plane, 3 ... n-type GaAs buffer layer, 4 ... n-type (Al _0.7 Ga _0.3 ) _0.5 In _0.5 P clad layer (clad layer of first conductivity type), 5... Active layer, 6... 1 p-type (Al _0.7 Ga _0.3 ) _0.5 In _0.5 P clad layer (first second layer) Conductive type cladding layer), 7... P-type Ga _0.5 In _0.5 P etching stop layer (second conductive type etching stop layer), 8... Second p-type (Al _0.7 Ga _0.3 ) _0.5 In _0.5 P cladding layer ( 2nd conductivity type cladding layer), 9 ... second p-type Ga _0.5 In _0.5 P etching stop layer, 10 ... third p-type (Al _0.7 Ga _0.3 ) _0.5 In _0.5 P cladding layer, 11 ... p-type In _0.5 Ga _0.5 P cap layer, 12,13,18,19 ... ridge, 14 n-type Al _0.5 In _0.5 P current confinement layer, 15 ... p-type GaAs contact layer, 16 ... p-type ohmic electrode, 17 ... resonator structure, LA ... semiconductor laser device, S1 ... first area, S2 ... second Area, S3, S4 ... Area.

Claims (3)

A first conductivity type AlGaInP clad that is sequentially stacked on the semiconductor substrate in the first and second regions when the gap between both cleavage surfaces of the first conductivity type semiconductor substrate is divided into a first region and a second region. A layer, an active layer, a first second conductivity type AlGaInP cladding layer,
A second second-conductivity-type AlGaInP clad layer and a third second-conductivity layer formed in a stripe shape on the first second-conductivity-type AlGaInP clad layer in the first region along the cleavage plane direction. A first ridge composed of a type AlGaInP cladding layer;
A second second conductivity type AlGaInP cladding layer formed on the first second conductivity type AlGaInP cladding layer in the second region;
A second ridge made of the third second conductivity type AlGaInP clad layer formed in a stripe shape on the second second conductivity type AlGaInP clad layer along the cleavage plane direction;
A pair of AlInP current confinement layers of a first conductivity type sandwiching the first and second ridges formed on the first and second conductivity type AlGaInP cladding layers;
A second conductivity type GaAs contact layer formed on the first and second ridges and the pair of first conductivity type AlInP current confinement layers;
A semiconductor laser device comprising: When dividing between the cleavage planes of the first conductivity type semiconductor substrate into the first region to the third region, the first conductivity sequentially stacked on the semiconductor substrate in the first region to the third region. Type AlGaInP cladding layer, active layer, first second conductivity type AlGaInP cladding layer, and
A second second-conductivity-type AlGaInP clad layer that is in the first region and is formed in a stripe shape on the first second-conductivity-type AlGaInP clad layer along the cleavage plane direction; A first ridge comprising an AlGaInP cladding layer of a third second conductivity type;
A second second conductivity type AlGaInP cladding layer formed on the first second conductivity type AlGaInP cladding layer in the second region;
The third second-conductivity-type AlGaInP clad formed in a stripe shape in the second region and on the second second-conductivity-type AlGaInP clad layer along the cleavage plane direction. A second ridge formed of a layer, connected to the first ridge, and formed by continuously reducing the width of the first ridge from the first region toward the third region; ,
The third second-conductivity-type AlGaInP clad formed in a stripe shape in the third region and on the second second-conductivity-type AlGaInP clad layer along the cleavage plane direction. A third ridge comprising a layer, connected to the second ridge, and having the same width as the second ridge;
A pair of first conductivity type AlInP current confinement layers sandwiching the first to third ridges formed on the first and second second conductivity type AlGaInP cladding layers;
A second conductivity type GaAs contact layer formed on the first to third ridges and the pair of first conductivity type AlInP current confinement layers;
A semiconductor laser device comprising:   The first region is a region surrounded by a surface perpendicular to the semiconductor substrate and the cleaved surface at a length position separated by 30 μm or more from either one of the two cleaved surfaces. The semiconductor laser device according to claim 1 or 2.

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