JP4897944B2 - Semiconductor laser device and manufacturing method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a highly reliable semiconductor laser element having proper laser characteristics. SOLUTION: This SAS semiconductor laser element 50 has the same constitution as that of the conventional SAS semiconductor laser element, having a two-layered etch stopping layer structure, except that an n-type GaAs layer 52 having a thickness of 10 nm is interposed between an n-type In0.49 Ga0.51 P second etch stopping layer 30 and an n-type Al0.35 Ga0.65 As current-blocking layer 32. Since the current-blocking layer 32 and second etch stopping layer 30 are separated from each other by the n-type GaAs layer 52, the interface between the layers 32 and 30 formed in the conventional SAS semiconductor laser element is not formed, an, accordingly, an intermediate layer in which many kinds of atoms are unevenly mixed will not be formed in the interface in this semiconductor laser element 50, unlike in the conventional SAS semiconductor laser element.

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a semiconductor laser device and a manufacturing method thereof, and more particularly, a semiconductor laser device having good laser characteristics and high reliability, for example, an internal constriction type (self-aligned structure, hereinafter referred to as SAS) in the 980 nm band. The present invention relates to a semiconductor laser element optimum as a semiconductor laser element and a method for manufacturing the same.
[0002]
[Prior art]
As a high-power semiconductor laser device used as an excitation light source for an erbium-doped optical fiber amplifier (EDFA) system, a 980 nm band SAS semiconductor laser device has been attracting attention, and its research and development is progressing.
In the process of fabricating the SAS semiconductor laser device having the internal stripe structure, when forming the current blocking structure, after forming the n-current blocking layer, the formed n-current blocking layer is etched into a stripe shape. Then, there is a step of forming a p-cladding layer.
[0003]
In order to fabricate a SAS semiconductor laser device having good laser characteristics, in the etching process, the etching depth is strictly controlled and only the etched layer is etched so that the underlying layer under the etched layer is not over-etched. It is extremely important.
Usually, the etching depth is adjusted by controlling the etching rate or the etching time, but it is difficult to adjust the etching depth to an accurate depth. Therefore, in order to accurately control the etching depth, an etching stop layer is often formed under the layer to be etched, and the progress of etching is often automatically stopped at the surface of the etching stop layer.
The etching stop layer is a material layer having an etching rate significantly lower than that of the layer to be etched with respect to an etching medium such as an etching gas or an etchant, that is, a material layer having etching selectivity, and is provided below the layer to be etched. By forming the layer, the progress of etching is automatically stopped at the etching stop layer due to the difference in the etching rate.
[0004]
In the production of a SAS semiconductor laser element or the like that requires strict control of the etching depth of the current blocking layer, particularly in the production of a high-power 980 nm band SAS semiconductor laser element that is attracting attention as an excitation light source for an EDFA system, An etch stop layer is essential.
[0005]
The 980 nm band SAS semiconductor laser includes an InGaAs layer as an active layer and an AlGaAs layer as a cladding layer on a GaAs substrate.
In the production, an n-AlGaAs cladding layer, an InGaAs active layer, a p-AlGaAs cladding layer, an n-AlGaAs current blocking layer, an n-GaAs cap layer, etc. are laminated on an n-GaAs substrate, and then an n-GaAs contact layer. And etching the n-AlGaAs current blocking layer to expose the p-AlGaAs cladding layer, an etch stop layer having an etching selectivity with respect to the AlGaAs layer and lattice-matching to the GaAs substrate._0.49Ga_0.51P layer is often used.
In addition, a structure in which an SCH layer made of non-doped AlGaAs is provided between the n-AlGaAs cladding layer and the InGaAs active layer and between the active layer and the p-AlGaAs cladding layer as required.
Furthermore, a method of providing an etching stop layer having a two-layer structure has been proposed as a proposal for improving a single etching stop layer.
[0006]
Here, with reference to FIGS. 3 and 4, a conventional method for fabricating a 980 nm band SAS semiconductor laser device will be described. 3 and 4 (a) to 4 (c) are cross-sectional views for each step when the stacked structure is etched by a conventional method in fabricating a 980 nm band SAS semiconductor laser device.
In this method, an etching stop layer having a two-layer structure is used when etching the GaAs layer and the AlGaAs current blocking layer.
First, as shown in FIG. 3, n-Al is formed on an n-GaAs substrate 12._0.3Ga_0.7As cladding layer 14, Al_0.2Ga_0.8AsSCH layer 16, GaAs_0.9P_0.1Barrier layer 18, In_0.2Ga_0.8As active layer 20, GaAs_0.9P_0.1Barrier layer 22 and Al_0.2Ga_0.8The AsSCH layer 24 is sequentially stacked.
Furthermore, Al_0.2Ga_0.8On the AsSCH layer 24, p-Al_0.3Ga_0.7As cladding layer 26, 10 nm thick p-GaAs first etching stop layer 28, 10 nm thick n-In_0.49Ga_0.51P second etching stop layer 30, n-Al having a thickness of 200 nm_0.35Ga_0.65A stacked structure of the As current blocking layer 32 and the p-GaAs cap layer 34 is formed.
[0007]
In order to fabricate a SAS semiconductor laser device, n-Al_0.35Ga_0.65Only the As current blocking layer 32 and the p-GaAs cap layer 34 need to be etched in stripes.
Therefore, the p-GaAs cap layer 34 and the n-Al_0.35Ga_0.65In order to etch the As current blocking layer 32, an etching mask 36 is formed as shown in FIG.
[0008]
Subsequently, as an etchant, n-In_0.49Ga_0.51Using an etching solution such as tartaric acid or citric acid that exhibits etching selectivity with respect to the P second etching stop layer 30, as shown in FIG. 4A, the p-GaAs cap layer 34 and the n-Al_0.35Ga_0.65The As current blocking layer 32 is etched. The progress of etching is expressed as n-In._0.49Ga_0.51After stopping at the P second etching stop layer 30, the etching mask 36 is removed by etching.
Next, as an etchant, a hydrochloric acid-based etchant (HCl: H: H) exhibiting etching selectivity with respect to the p-GaAs first etching stop layer 28.₂PO_Four= 1: 3), as shown in FIG. 4B, n-In_0.49Ga_0.51The P second etching stop layer 30 is etched and removed. The progress of etching stops at the p-GaAs first etching stop layer 28.
[0009]
Next, as shown in FIG. 4C, on the p-GaAs cap layer 34 and the p-GaAs first etching stop layer 28, p-Al._0.3Ga_0.7The As cladding layer 38 and the p-GaAs cap layer 34 are regrown.
Thereby, the laser structure 40 of the SAS semiconductor laser element in the 980 nm band can be manufactured.
[0010]
[Problems to be solved by the invention]
However, when a 980 nm band SAS semiconductor laser device is fabricated by the conventional method described above, n-In_0.49Ga_0.51P second etching stop layer 30 and n-Al_0.35Ga_0.65By forming an intermediate layer having a composition different from both compositions at the interface with the As current blocking layer 32, n-In_0.49Ga_0.51The resistance of the P second etching stop layer 30 decreases, and p-Al_0.3Ga_0.7As cladding layer 26 is exposed to the regrowth surface. As a result, for example, there is a problem that the operating voltage and the threshold current are extremely high.
That is, the laser characteristics and reliability are not necessarily at a level that can be practically satisfied, and further improvements have been desired.
[0011]
For example, an antireflection film having a stripe width of 2.5 μm, a resonator length of 1200 μm, a reflectivity of 5% on the exit end face, and a highly reflective film having a reflectivity of 92% on the end face opposite to the exit end face are provided. In fabricating the laser structure 40, the p-GaAs cap layer 34 and the n-Al_0.35Ga_0.65When etching the As current blocking layer 32, the resistance of the second etching stop layer 30 is maintained, and when the etching stops at the second etching stop layer 30, the threshold current of the fabricated laser structure 40 is 17 mA, The operating voltage was 1.4 V when the injection current was 100 mA.
On the other hand, when the same laser structure 40 is produced, the resistance of the second etching stop layer 30 decreases, and p-Al_0.3Ga_0.7When the As cladding layer 26 was exposed to the regrowth surface, the threshold current increased from 40 mA to 100 mA, and the operating voltage when the injection current was 100 mA increased from 1.7 V to 2.0 V.
[0012]
In the above description, the problem between the etching target layer and the etching stop layer is explained by taking the problem of the etching stop layer having the two-layer structure when manufacturing the 980 nm band SAS semiconductor laser element as an example. However, this problem is not limited to the etching stop layer having the two-layer structure, and is not limited to the fabrication of the 980 nm band SAS semiconductor laser device, but occurs between the etching target layer and the etching stop layer.
When fabricating a semiconductor laser device, the compound semiconductor layer is often etched into a desired shape. For example, in the formation of a ridge, the upper part of the stacked structure of the compound semiconductor layer is etched, and the diffraction grating In formation or the like, one compound semiconductor layer is etched. Even in this case, when the etching stop layer is formed under the layer to be etched, the same problem as the above-described example occurs.
[0013]
Therefore, an object of the present invention is to provide a semiconductor laser element manufactured by controlling the etching depth of a compound semiconductor layer thereon by an etching stop layer made of a compound semiconductor layer, and has good laser characteristics and reliability. It is to provide a semiconductor laser device and to provide a method for manufacturing such a semiconductor laser device.
[0014]
[Means for Solving the Problems]
The present inventor has investigated the causes of undesirable laser characteristics and reliability of the 980 nm band SAS semiconductor laser device manufactured by the conventional method described above, and found the following.
n-In_0.49Ga_0.51N-Al on the P second etching stop layer 30_0.35Ga_0.65When the As current blocking layer 32 is grown, as shown in FIG. 5A, an intermediate layer having a non-uniform composition in which the constituent atoms of the second etching stop layer 30 and the current blocking layer 32 are mixed at the interface. 31 is formed.
When growing the current blocking layer 32 on the second etching stop layer 30, when the growth of the current blocking layer 32 progresses ideally, for example, when growing the current blocking layer 32 under experimentally ideal conditions, Although the layer 31 is not formed, when the current blocking layer 32 is grown at a practical speed by an MOCVD method or the like in an actual growth process, the intermediate layer 31 in which constituent atoms are mixed in a complicated manner is formed.
In the intermediate layer 31, the etching rate is also non-uniform, so that n-Al_0.35Ga_0.65When the As current blocking layer 32 is etched, n-In_0.49Ga_0.51The surface of the P second etching stop layer 30 is etched unevenly, resulting in a rough surface.
Therefore, n-In_0.49Ga_0.51When the P second etching stop layer 30 is as thin as 10 nm or less, as shown in FIG._0.49Ga_0.51A hole is locally opened in the P second etching stop layer 30, and the p-GaAs first etching stop layer 28 and the p-Al layer thereunder are formed._0.3Ga_0.7The As cladding layer 26 is etched.
[0015]
P-Al_0.3Ga_0.7When the As cladding layer 26, that is, the Al-based material is exposed at the regrowth interface, surface oxidation of the Al material occurs, and thus p-Al_0.3Ga_0.7Crystal defects occur when the As cladding layer 38 is regrown. For this reason, the laser characteristics and reliability of the SAS semiconductor laser element are degraded.
For example, p-Al exposed on the surface_0.3Ga_0.7On the As cladding layer 26, p-Al_0.3Ga_0.7The As cladding layer 38 was regrown to produce a SAS semiconductor laser device, and the laser characteristics were evaluated. As a result, the operating voltage and the threshold were significantly increased.
[0016]
N-Al_0.35Ga_0.65As current blocking layer 32 / n-In_0.49Ga_0.51When an intermediate layer is formed at the interface of the P second etching stop layer 30, n-In_0.49Ga_0.51When the P second etching stop layer 30 is removed by etching, n-In around the intermediate layer_0.49Ga_0.51There is also a problem that it becomes difficult to remove the P second etching stop layer 30 locally.
[0017]
Therefore, the present inventor inserts a compound semiconductor layer different from both the current blocking layer 32 and the second etching stop layer 30 between the current blocking layer 32 and the second etching stop layer 30, for example, a GaAs layer, The current blocking layer 32 and the second etching stop layer 30 are separated from each other to prevent the formation of an intermediate layer, thereby improving the etching resistance of the second etching stop layer 30 and repeated experiments. Invented the invention.
[0018]
  In order to achieve the above object, based on the above-described knowledge, a semiconductor laser device according to the present invention includes a first compound semiconductor layer in a compound semiconductor stack constituting a laser structure,AboveUnder the first compound semiconductor layerAboveAn etching stop layer comprising a compound semiconductor layer different from the first compound semiconductor layer,AboveWhen etching the first compound semiconductor layer,AboveIn the semiconductor laser device manufactured by controlling the etching depth by the etching stop layer,AboveA first compound semiconductor layer;AboveBetween the etching stop layer,AboveA first compound semiconductor layer andAboveA second compound semiconductor layer different from both of the etching stop layer is interposed,The first compound semiconductor layer, the etching stop layer, and the second compound semiconductor layer are an AlGaAs layer, an InGaP layer, and a GaAs layer, respectively.It is characterized by that.
[0019]
In the present invention, the thickness of the first compound semiconductor layer and the etching stop layer is not limited, but the thickness of the second compound semiconductor layer is 0.3 nm or more. This is because the effect of the present invention is poor at 0.3 nm or less.
In the present invention, an intermediate layer is formed by interposing a second compound semiconductor layer different from the etched layer and the etching stop layer between the first compound semiconductor layer as the etched layer and the etching stop layer. By preventing this, the etching resistance of the etching stop layer can be improved.
In the present invention, the intermediate layer is a material different from the first compound semiconductor layer and the etching stop layer, and is a layer having a non-uniform composition in which constituent atoms of the first compound semiconductor layer and the etching stop layer are mixed in a complicated manner. Say.
[0020]
When controlling the etching of the AlGaAs layer using the InGaP etching stop layer, the present invention is applied to interpose the GaAs layer between the InGaP etching stop layer and the AlGaAs layer, thereby improving the resistance of the InGaP etching stop layer. Can be significantly improved.
[0021]
The present invention and the later-described method of the present invention can be suitably applied to a combination of an etched layer and an etching stop layer, in which the above-described intermediate layer is easily formed between the etched layer and the etching stop layer.
[0022]
Preferably, the second compound semiconductor layer has a material that is different from the materials of both the first compound semiconductor layer and the etching stop layer and lattice-matched with the substrate.
In an embodiment of the present invention suitable for a 980 nm SAS semiconductor laser element having a combination of an etched layer of an AlGaAs layer and an etching stop layer of an InGaP layer, the first compound semiconductor layer is a compound semiconductor layer containing at least Al. In addition, the etching stop layer is a compound semiconductor layer containing at least P, and the second compound semiconductor layer is a compound semiconductor layer not containing both Al and P.
[0023]
  A method of manufacturing a semiconductor laser device according to the present invention includes an etching stop layer made of a compound semiconductor as a part of a compound semiconductor stack constituting the semiconductor laser device, followed byAboveOn the etching stop layerAboveForming a first compound semiconductor layer having a composition different from that of the etching stop layer;AboveWhen etching the first compound semiconductor layer,AboveA method of manufacturing a semiconductor laser device by controlling an etching depth with an etching stop layer,AboveAfter depositing the etching stop layer,AboveA first compound semiconductor layer andAboveForming a second compound semiconductor layer different from both of the etching stop layers;AboveOn the second compound semiconductor layerAboveForming a first compound semiconductor layer; andAboveTo the etching stop layer,AboveA first compound semiconductor layer andAboveEtching the second compound semiconductor layer,The first compound semiconductor layer, the etching stop layer, and the second compound semiconductor layer are an AlGaAs layer, an InGaP layer, and a GaAs layer, respectively.It is characterized by that.
[0024]
  Furthermore, when providing an etching stop layer having a two-layer structure,AboveBefore forming an etching stop layer (hereinafter referred to as a first etching stop layer) on the base layer,AboveOn the underlayerAboveForming a second etching stop layer made of a compound semiconductor layer having etching selectivity with respect to the first etching stop layer;AboveUsing the second etching stop layer as an etching stop layer,AboveEtching the first etching stop layer.
[0025]
In the method of the present invention, the second compound semiconductor layer is interposed between the layer to be etched and the etching stop layer to prevent the formation of the intermediate layer, thereby improving the etching stop resistance of the etching stop layer, and the etching stop layer. This improves the controllability of selective etching of the semiconductor layer using.
[0026]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described specifically and in detail with reference to the accompanying drawings.
Embodiment of semiconductor laser device
The present embodiment is an example of an embodiment in which the semiconductor laser device according to the present invention is applied to a 980 nm band SAS semiconductor laser device, and FIG. 1 is a cross-sectional view showing the configuration of the SAS semiconductor laser device of the present embodiment. It is.
As shown in FIG. 1, the SAS semiconductor laser device 50 according to the present embodiment includes an n-In_0.49Ga_0.51P second etching stop layer 30 and n-Al_0.35Ga_0.65The structure is the same as that of the conventional SAS semiconductor laser element 40 except that an n-GaAs layer 52 having a thickness of 5 nm is interposed between the As current blocking layer 32.
In the SAS semiconductor laser element 50, a p-side electrode 54 is formed on the p-GaAs cap layer 34, and an n-side electrode 56 is formed on the back surface of the n-GaAs substrate 12.
[0027]
In the SAS semiconductor laser device 50 according to this embodiment, the n-GaAs layer 52 is interposed, so that n-Al_0.35Ga_0.65As current blocking layer 32 and n-In_0.49Ga_0.51Since the P second etching stop layer 30 is separated from each other, as in the conventional case, n-Al_0.35Ga_0.65As current blocking layer 32 and n-In_0.49Ga_0.51An interface with the P second etching stop layer 30 is not formed, and therefore, an intermediate layer in which various atoms are mixed non-uniformly is not formed at the interface.
The fact that the intermediate layer is not formed can be confirmed with a transmission electron microscope, and the operating voltage and threshold value of the SAS semiconductor laser device 50 of the present embodiment are the same as those of the n-GaAs layer 52. Compared with the SAS semiconductor laser element not interposing, it was significantly lower.
[0028]
Embodiment of manufacturing method of semiconductor laser device
The present embodiment is an example of an embodiment when the method for fabricating a semiconductor laser device according to the present invention is applied to the fabrication of the SAS semiconductor laser device 50 described above. FIGS. 2A to 2C are cross-sectional views for each process when a SAS semiconductor laser device is manufactured according to the method of this embodiment.
In the same manner as the conventional method described above, first, as shown in FIG. 2A, an n-Al substrate is formed on an n-GaAs substrate 12._0.3Ga_0.7As cladding layer 14, Al_0.2Ga_0.8AsSCH layer 16, GaAs_0.9P_0.1Barrier layer 18, In_0.2Ga_0.8As active layer 20, GaAs_0.9P_0.1Barrier layer 22 and Al_0.2Ga_0.8The AsSCH layer 24 is sequentially stacked.
[0029]
Furthermore, Al_0.2Ga_0.8On the AsSCH layer 24, p-Al_0.3Ga_0.7As cladding layer 26, 10 nm thick p-GaAs first etching stop layer 28, 10 nm thick n-In_0.49Ga_0.51P second etching stop layer 30, 5 nm thick GaAs layer 52, 200 nm thick n-Al_0.35Ga_0.65A stacked structure of the As current blocking layer 32 and the p-GaAs cap layer 34 is formed.
Next, as shown in FIG. 2A, the p-GaAs cap layer 34, n-Al_0.35Ga_0.65In order to etch the As current blocking layer 32, an etching mask 36 is formed.
[0030]
Subsequently, as an etchant, n-In_0.49Ga_0.51Using an etchant such as tartaric acid or citric acid having etching selectivity with respect to the P second etching stop layer 30, as shown in FIG. 2B, the p-GaAs cap layer 34, n-Al_0.35Ga_0.65The As current blocking layer 32 and the n-GaAs layer 52 are etched. The progress of etching is expressed as n-In._0.49Ga_0.51After stopping at the P second etching stop layer 30, the etching mask 36 is removed.
Next, as an etchant, a hydrochloric acid-based etchant (HCl: H: H) exhibiting etching selectivity with respect to the p-GaAs first etching stop layer 28.₂PO_Four= 1: 3), as shown in FIG. 2 (c), n-In_0.49Ga_0.51The P second etching stop layer 30 is etched and removed.
[0031]
Next, p-Al is formed on the p-GaAs cap layer 34 and the exposed p-GaAs first etching stop layer 28._0.3Ga_0.7The As current cladding layer 38 and the p-GaAs cap layer 34 are regrown.
Next, a p-side electrode 54 is formed on the p-GaAs cap layer 34, and an n-side electrode 56 is formed on the back surface of the n-GaAs substrate 12, whereby a 980 nm band SAS semiconductor laser device is formed as shown in FIG. The laser structure 50 can be manufactured.
[0032]
In the method of the present embodiment, the n-Al layer 52 is interposed, so that n-Al_0.35Ga_0.65As current blocking layer 32 and n-In_0.49Ga_0.51Since the P second etching stop layer 30 is separated from each other, as in the conventional case, n-Al_0.35Ga_0.65As current blocking layer 32 and n-In_0.49Ga_0.51An interface with the P second etching stop layer 30 is not formed, and therefore, an intermediate layer in which various atoms are mixed non-uniformly is not formed at the interface.
Therefore, n-Al_0.35Ga_0.65When the As current blocking layer 32 is etched, the surface roughness is n-In as in the prior art._0.49Ga_0.51It does not occur in the P second etching stop layer 30.
[0033]
Further, as in the prior art, by forming the intermediate layer, n-In_0.49Ga_0.51The composition of the P second etching stop layer 30 fluctuates locally, and n-Al_0.35Ga_0.65When etching the As current blocking layer 32, it is not difficult to exist in a uniform film thickness over the entire layer, so that the etching stop resistance of the second etching stop layer 30 is improved, and the second etching stop is temporarily assumed. Even if the film thickness of the layer 30 is 10 nm or less, it is not etched and a hole is not locally opened.
In fact, it was confirmed by observation with a reflection electron microscope that etching stop resistance was improved and a regrown interface without surface roughness was obtained.
[0034]
Furthermore, since the formation of the intermediate layer is prevented by inserting the n-GaAs layer 52, n-In_0.49Ga_0.51When the P second etching stop layer 30 is etched, there is no problem that it is difficult to smoothly etch the second etching stop layer 30 because an intermediate layer is formed as in the prior art.
When the laser characteristics of the SAS semiconductor laser device manufactured according to the method of the present embodiment were measured, the operating voltage and the threshold value were Al on the surface because no GaAs layer was interposed._0.3Ga_0.7The As cladding layer was significantly lower than the conventional SAS semiconductor laser device exposed on the surface.
[0035]
The effect of the present embodiment can be applied not only to the combination of the etching target layer of the AlGaAs layer and the etching stop layer of the InGaP layer, but also to other system combinations.
That is, the etching resistance of the etching stop layer can be improved by inserting the second compound semiconductor layer that prevents the formation of the intermediate layer at the interface between the semiconductor layers of other material systems in which the intermediate layer having a nonuniform composition is easily formed. Can be improved.
[0036]
【The invention's effect】
According to the present invention, in the semiconductor laser device manufactured by etching the first compound semiconductor layer while controlling the etching depth by the etching stop layer, between the first compound semiconductor layer and the etching stop layer, By interposing the second compound semiconductor layer different from both the first compound semiconductor layer and the etching stop layer, the etching resistance of the etching stop layer can be improved, and the semiconductor laser having good laser characteristics and high reliability. An element can be realized.
According to the method of the present invention, the resistance of the etching stop layer is improved by inserting the second compound semiconductor layer between the first compound semiconductor layer and the etching stop layer, and the etching control in the semiconductor laser manufacturing process. Accuracy can be improved.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a configuration of a SAS semiconductor laser device according to an embodiment.
FIGS. 2A to 2C are cross-sectional views for each process when a SAS semiconductor laser device is manufactured according to the method of the embodiment. FIG.
FIG. 3 is a cross-sectional view for each step when a laminated structure is etched by a conventional method in fabricating a 980 nm band SAS semiconductor laser device.
4 (a) to 4 (c) are cross-sectional views for each step when etching a laminated structure by a conventional method in fabricating a 980 nm band SAS semiconductor laser device, following FIG. 3, respectively. FIG.
FIGS. 5A and 5B are schematic cross-sectional views illustrating problems in a conventional etching method using an etching stop layer for etching control, respectively.
[Explanation of symbols]
12 n-GaAs substrate
14 n-Al_0.3Ga_0.7As cladding layer
16 Al_0.2Ga_0.8AsSCH layer
18 GaAs_0.9P_0.1Barrier layer
20 In_0.2Ga_0.8As active layer
22 GaAs_0.9P_0.1Barrier layer
24 Al_0.2Ga_0.8AsSCH layer
26 p-Al_0.3Ga_0.7As cladding layer
28 p-GaAs first etching stop layer
30 n-In_0.49Ga_0.51P second etching stop layer
32 n-Al_0.35Ga_0.65As current blocking layer
34 p-GaAs cap layer
38 p-Al_0.3Ga_0.7As cladding layer
50 SAS Semiconductor Laser Device in 980 nm Band of Example Embodiment
52 n-GaAs layer
54 p-side electrode
56 n-side electrode
36 Etching mask
Laser structure of 40 980 nm band SAS semiconductor laser device

Claims (5)

The compound semiconductor stack constituting the laser structure, a first compound semiconductor layer, and an etch stop layer of different compound semiconductor layer and the first compound semiconductor layer under the first compound semiconductor layer, when etching the first compound semiconductor layer, a semiconductor laser element manufactured by controlling the etching depth by the etching stop layer, between the etching stop layer and the first compound semiconductor layer, both different from the second compound semiconductor layer of the first compound semiconductor layer and the etching stop layer is interposed,
The first compound semiconductor layer, the etching stop layer, and the second compound semiconductor layer are an AlGaAs layer, an InGaP layer, and a GaAs layer, respectively.
The semiconductor laser device, wherein the first compound semiconductor layer functions as a current blocking layer . As part of a compound semiconductor lamination that constitute the semiconductor laser element, the etching stop layer made of a compound semiconductor, followed by said etching stop layer is deposited a first compound semiconductor layer having different compositions to the etching stop layer and then in etching the first compound semiconductor layer, by controlling the etching depth by the etching stop layer, a method of making a semiconductor laser device,
After forming the etching stop layer, a step of forming both different from the second compound semiconductor layer of the first compound semiconductor layer and the etching stop layer,
A step of forming the first compound semiconductor layer on the second compound semiconductor layer,
Then, until said etch stop layer, and a step of etching the first compound semiconductor layer and the second compound semiconductor layer,
The first compound semiconductor layer, the etching stop layer, and the second compound semiconductor layer are an AlGaAs layer, an InGaP layer, and a GaAs layer, respectively.
The method for manufacturing a semiconductor laser element, wherein the first compound semiconductor layer functions as a current blocking layer . The etch stop layer before depositing (hereinafter, first referred to as an etching stop layer) and underlayer, a compound semiconductor layer having an etch selectivity with respect to the first etching stop layer on the underlying layer Forming a second etching stop layer comprising:
Wherein the second etching stop layer as an etch stop layer, a method for manufacturing a semiconductor laser device according to claim 2, characterized in that it comprises a step of etching the first etching stop layer. The compound semiconductor stack constituting the laser structure, a first compound semiconductor layer, and an etch stop layer of different compound semiconductor layer and the first compound semiconductor layer under the first compound semiconductor layer, when etching the first compound semiconductor layer, a semiconductor laser element manufactured by controlling the etching depth by the etching stop layer, between the etching stop layer and the first compound semiconductor layer, both different from the second compound semiconductor layer of the first compound semiconductor layer and the etching stop layer is interposed,
The first compound semiconductor layer, the etching stop layer, and the second compound semiconductor layer are an AlGaAs layer, an InGaP layer, and a GaAs layer, respectively.
The second compound semiconductor layer functions as a mixed crystallization suppressing layer that prevents non-uniform mixing of various atoms at the interface between the first compound semiconductor layer and the etching stop layer. A semiconductor laser device. As part of a compound semiconductor lamination that constitute the semiconductor laser element, the etching stop layer made of a compound semiconductor, followed by said etching stop layer is deposited a first compound semiconductor layer having different compositions to the etching stop layer and then in etching the first compound semiconductor layer, by controlling the etching depth by the etching stop layer, a method of making a semiconductor laser device,
After forming the etching stop layer, a step of forming both different from the second compound semiconductor layer of the first compound semiconductor layer and the etching stop layer,
A step of forming the first compound semiconductor layer on the second compound semiconductor layer,
Then, until said etch stop layer, and a step of etching the first compound semiconductor layer and the second compound semiconductor layer,
The first compound semiconductor layer, the etching stop layer, and the second compound semiconductor layer are an AlGaAs layer, an InGaP layer, and a GaAs layer, respectively.
The second compound semiconductor layer functions as a mixed crystallization suppressing layer that prevents non-uniform mixing of various atoms at the interface between the first compound semiconductor layer and the etching stop layer. A method for manufacturing a semiconductor laser device.

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