JP2000091696A - Semiconductor element, semiconductor light-emitting element and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a semiconductor element and a semiconductor light-emitting element of high reproducibility which control the depth of etching with high accuracy. SOLUTION: On a sapphire substrate 1, a transparent n-AlGaN first clad layer 6, a transparent MQW light-emitting layer 7 and a transparent p-AlGaN second clad layer 8 are continuously grown, and an opaque low-temperature growth layer 9 consisting of p-InGaN whose substrate temperature is 600-750 deg.C is grown further thereon. Further, a transparent p-AlGaN third clad layer 10 and a p-GaN contact layer 11 are grown in this order. Then, an Ni mask 16 is formed in a stripe area on the p-contact layer 11, and a part of the area from the p-contact layer 11 to the p-low temperature growth layer 9 is removed by etching in an RIE method, so that the opaque surface of a semiconductor wafer of the area in which the opaque p-low-temperature growth layer 9 is removed turns into transparent.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to GaN (gallium nitride), AlN (aluminum nitride) or InN.
The present invention relates to a semiconductor device having a compound semiconductor layer made of a group III-V nitride-based semiconductor (hereinafter, referred to as a nitride-based semiconductor) such as (indium nitride) or a mixed crystal thereof, a semiconductor light-emitting device, and a method of manufacturing the same.

[0002]

2. Description of the Related Art At present, there is an increasing demand for an optical disk system having a higher density and a larger capacity than a digital video disk. Research and development of GaN-based semiconductor laser devices that emit blue or violet light have been actively conducted as light sources to satisfy such demands.

Various reports and proposals have been made on a method of controlling the transverse mode of a GaN-based semiconductor laser device. Most of these lateral mode control methods are a ridge waveguide structure and a self-aligned structure employed in a conventional semiconductor laser device that generates red light or infrared light.

In a manufacturing process of a GaN-based semiconductor laser device having a ridge waveguide structure or a self-aligned structure, etching is performed to form an optical waveguide.

When etching a semiconductor layer such as AlGaAs or InGaAlP used for a semiconductor laser device that generates red light or infrared light, wet etching is performed by immersing the semiconductor layer in an etchant to melt a desired portion. Will be In wet etching, a desired layer can be selectively etched by providing an etching stop layer having a composition different from that of a layer to be removed by etching in a semiconductor layer forming a semiconductor laser element ( Composition selective etching). This allows
It is possible to control the etching depth with high accuracy.

[0006]

SUMMARY OF THE INVENTION However, GaN
Each semiconductor layer in a system-based semiconductor laser device is chemically stable and therefore has excellent chemical resistance. Therefore, it is impossible to perform the above wet etching. Therefore, when manufacturing a GaN-based semiconductor laser device, RIE (reactive ion etching), RIBE
Dry etching such as a reactive ion beam etching method is used. In these dry etchings, since etching is performed by ion bombardment, the above-described composition selective etching cannot be performed, and the etching depth is adjusted by the etching time.
For this reason, it is difficult to control the etching depth with high accuracy, and it is impossible to perform the etching with good reproducibility. As a result, when a plurality of semiconductor laser elements are formed, characteristics of the individual semiconductor laser elements tend to vary.

An object of the present invention is to provide a semiconductor device and a semiconductor light emitting device which have high reproducibility and have device characteristics with little variation between devices.

Another object of the present invention is to provide a semiconductor device and a method of manufacturing a semiconductor light emitting device which can control the etching depth with high accuracy and have high reproducibility.

[0009]

Means for Solving the Problems and Effects of the Invention A semiconductor device according to a first aspect of the present invention is a semiconductor device comprising a transparent first nitride-based semiconductor layer containing at least one of gallium, aluminum and indium. An opaque etching marker layer and a transparent second nitride-based semiconductor layer containing at least one of gallium, aluminum and indium are sequentially formed.

In the semiconductor device according to the present invention, the region where the etching marker layer is present appears opaque, while the region where the etching marker layer is not present appears transparent.

When the etching marker layer is removed by etching during the manufacture of a semiconductor device, the surface of the semiconductor wafer changes from opaque to transparent.

Therefore, when a predetermined region of the second nitride-based semiconductor layer on the first nitride-based semiconductor layer is removed by etching, the change in the color of the surface of the semiconductor wafer is used to remove the etching marker layer. Since etching can be stopped accurately, highly accurate etching can be performed. As a result, the reproducibility of the device characteristics of the semiconductor device is improved, and the variation of the device characteristics among the devices is reduced.

According to a second aspect of the present invention, there is provided a semiconductor light emitting device, wherein at least one of gallium, aluminum and indium is formed on a first cladding layer made of a transparent nitride-based semiconductor containing at least one of gallium, aluminum and indium. And a second cladding layer made of a transparent nitride-based semiconductor containing at least one of gallium, aluminum and indium, and are sequentially formed on the second cladding layer. Opaque etching marker layer and at least one of gallium, aluminum and indium
And a third cladding layer made of a transparent nitride-based semiconductor including at least one of them.

In the semiconductor light emitting device according to the present invention,
A ridge portion including an etching marker layer and a third cladding layer is formed in a striped region on the second cladding layer. An optical waveguide is formed in the light emitting layer below the ridge.

In this semiconductor light emitting device, the region where the etching marker layer exists appears opaque, while the region where the etching marker layer does not exist appears transparent. Therefore, when the etching marker layer is removed by etching during the manufacture of the semiconductor light emitting device, the surface of the semiconductor wafer changes from opaque to transparent.

The ridge portion is formed by etching and removing the third cladding layer and the etching marker layer except for the stripe-shaped region. At the time of such etching, the etching can be accurately stopped at the etching marker layer by utilizing the change in the color of the semiconductor wafer surface. Therefore, the etching can be stopped with good reproducibility immediately after the etching marker layer is removed. Therefore, the reproducibility of the device characteristics in the semiconductor light emitting device is improved, and the variation in device characteristics between the devices is reduced.

According to a third aspect of the present invention, there is provided a semiconductor light emitting device, wherein at least one of gallium, aluminum and indium is formed on a first cladding layer made of a transparent nitride-based semiconductor containing at least one of gallium, aluminum and indium. And a second cladding layer made of a transparent nitride-based semiconductor containing at least one of gallium, aluminum and indium, and are sequentially formed on the second cladding layer. An opaque etching marker layer and a transparent current blocking layer are sequentially formed on a region excluding the stripe region of FIG. 1, and a transparent nitride-based semiconductor containing at least one of gallium, aluminum, and indium on the stripe region A third cladding layer made of

In the semiconductor light emitting device according to the present invention,
A stripe-shaped opening is formed in the current blocking layer and the etching marker layer, and an optical waveguide is formed in the light-emitting layer below the stripe-shaped opening.

In this semiconductor light emitting device, the region where the etching marker layer exists appears opaque, while the region where the etching marker layer does not exist appears transparent. Therefore, when the etching marker layer is removed during the manufacture of the semiconductor light emitting device, the surface of the semiconductor wafer changes from opaque to transparent.

The above-mentioned striped openings are formed by removing the current blocking layer and the etching marker layer on the second cladding layer by etching except for the striped regions. At the time of such etching, the etching can be accurately stopped at the etching marker layer by utilizing the change in the color of the semiconductor wafer surface. Therefore, the etching can be stopped with good reproducibility immediately after the etching marker layer is removed. Therefore, the reproducibility of the device characteristics in the semiconductor light emitting device is improved, and the variation in device characteristics between the devices is reduced.

In a semiconductor light emitting device according to a fourth aspect of the present invention, an opaque etching marker layer is formed in a predetermined region on a transparent first nitride semiconductor layer containing at least one of gallium, aluminum and indium, A transparent second nitride-based semiconductor layer including a light-emitting layer and at least one of gallium, aluminum, and indium is formed on the etching marker layer, and a first electrode is formed on the first nitride-based semiconductor layer. It is formed and a second electrode is formed on the second nitride-based semiconductor layer.

In the semiconductor light emitting device according to the present invention, the region where the etching marker layer exists appears opaque, while the region where the etching marker layer does not exist appears transparent. Therefore, when the etching marker layer is removed by etching during the manufacture of the semiconductor light emitting device, the surface of the semiconductor wafer changes from opaque to transparent.

In this semiconductor light emitting device, the etching can be accurately stopped at the etching marker layer by utilizing the change in the color of the surface of the semiconductor wafer.
Therefore, the reproducibility of the device characteristics of the semiconductor light emitting device is improved, and variations in device characteristics between the devices are reduced.

In the semiconductor light emitting device according to any one of the second to fourth inventions, the etching marker layer is
It is preferably a nitride-based semiconductor layer containing gallium and indium grown at a temperature of up to 750 ° C.

The nitride semiconductor layer containing gallium and indium grown at the above temperature becomes opaque and black. Although the surface of a semiconductor wafer having such a nitride-based semiconductor layer as an etching marker layer looks opaque, the surface of the semiconductor wafer becomes transparent when the etching marker layer is removed by etching. By utilizing such a change in the color of the semiconductor wafer surface, the etching can be accurately stopped at the etching marker layer.

Further, since the nitride semiconductor containing gallium and indium is a III-V group nitride semiconductor,
Even if it is inserted into a semiconductor light-emitting device made of a nitride-based semiconductor containing at least one of gallium, aluminum and indium, the device characteristics do not deteriorate.

According to a fifth aspect of the invention, there is provided a method of manufacturing a semiconductor device, comprising: forming a transparent first nitride-based semiconductor layer containing at least one of gallium, aluminum, and indium; Forming an opaque etching marker layer on the layer, forming a transparent second nitride-based semiconductor layer containing at least one of gallium, aluminum and indium on the etching marker layer; Removing predetermined regions of the physical semiconductor layer and the etching marker layer by etching.

In the method of manufacturing a semiconductor device according to the present invention, a transparent first nitride-based semiconductor layer, an opaque etching marker layer and a transparent second nitride-based semiconductor layer are successively grown. In this case, the surface of the semiconductor wafer appears opaque due to the presence of the opaque etching marker layer.

While observing the surface of the semiconductor wafer visually or with a microscope, predetermined regions of the second nitride-based semiconductor layer and the etching marker layer are removed by etching. The surface of the semiconductor wafer in the area where the etching marker layer has been removed changes from opaque to transparent. Etching is stopped when such a change in the surface of the semiconductor wafer is confirmed.

According to the method of manufacturing a semiconductor device as described above, it is possible to accurately remove predetermined regions of the second nitride-based semiconductor layer and the etching marker layer by etching. As described above, since the etching depth can be controlled with high accuracy, the reproducibility of the device characteristics of the semiconductor device is improved, and the variation in device characteristics between the devices is reduced.

The etching marker layer is a nitride-based semiconductor layer containing gallium and indium, and the growth temperature of the etching marker layer may be set lower than the growth temperatures of the first and second nitride-based semiconductor layers. preferable.

Thus, the same forming method as the first and second nitride-based semiconductor layers except that the growth temperature of the etching marker layer is set lower than that of the first and second nitride-based semiconductor layers. More etching marker layers can be formed. Therefore, it becomes easy to manufacture a semiconductor device having an etching marker layer.

The nitride-based semiconductor layer containing gallium and indium grown in this manner becomes opaque and black. Although the surface of a semiconductor wafer having such a nitride-based semiconductor layer as an etching marker layer looks opaque, the surface of the semiconductor wafer becomes transparent when the etching marker layer is removed by etching. Thus, by observing the surface of the semiconductor wafer, it can be easily confirmed whether or not the etching marker layer has been removed by the etching. Therefore, it is possible to control the etching depth with high accuracy.

Further, since the nitride semiconductor containing gallium and indium is a III-V group nitride semiconductor,
Even if it is inserted into a semiconductor device made of a nitride-based semiconductor containing at least one of gallium, aluminum and indium, the device characteristics do not deteriorate.

[0035]

FIG. 1 is a sectional view showing the structure of a GaN-based semiconductor laser device according to a first embodiment of the present invention.

The semiconductor laser device shown in FIG. 1 is a semiconductor laser device having a ridge waveguide structure. Note that Si is used as an n-type dopant in each layer in FIG. 1 and Mg is used as a p-type dopant.

On the c-plane of the sapphire substrate 1, a buffer layer 2 of undoped Al _0.5 Ga _0.5 N having a thickness of 300 °, an undoped GaN layer 3 having a thickness of 2 μm, and a thickness of 3 μm
m-n-GaN layer 4, n-In _0.1 Ga _0.9 N, 0.1 μm-thick n-crack preventing layer 5, n-Al _0.15
A 0.7 μm-thick n-first cladding layer 6 made of Ga _0.85 N and a multiple quantum well light emitting layer (hereinafter referred to as MQW light emitting layer) 7 are sequentially formed.

As shown in the energy band diagram of FIG. 2, the MQW light emitting layer 7 has six In _0.03 Ga layers having a thickness of 60 °.
_0.97 N quantum barrier layer 71 and five 30 mm thick In _0.18 G
a _0.82 N quantum well layers 72 are included in a multiple quantum well structure alternately stacked. Both surfaces of the multiple quantum well structure are sandwiched between GaN optical guide layers 73 having a thickness of 0.1 μm.

Further, on the MQW light emitting layer 7, p-Al
_A 0.2 μm thick p-second cladding layer 8 made of _0.15 Ga _0.85 N is formed. p-In _0.1 Ga is formed in a stripe region at the center on the p-second cladding layer 8.
P-low temperature growth layer 9 of _0.9- N thickness 0.05-0.1 μm, 0.4-μ thickness of p-Al _0.15 Ga _0.85 N
m-third cladding layer 10 and 0.2 μm thick p
A p-contact layer 11 made of -GaN is formed in order.

P-low temperature growth layer 9, p-third cladding layer 1
0 and the p-contact layer 11 constitute a ridge portion, and the p-second cladding layer 8 constitutes a flat portion of the cladding layer. Further, a part of the region from the p-second cladding layer 8 to the n-GaN layer 4 has been removed by etching,
The n-GaN layer 4 is exposed.

Further, in order to perform current confinement and protect the exposed portion of the pn junction, except for the upper surface of the p-contact layer 11 and the electrode formation region of the n-GaN layer 4, both sides of the ridge portion, the cladding layer The SiO ₂ film 14 is formed on the upper surface of the flat portion, the upper surface of the n-GaN layer 4 and the side surfaces from the p-second cladding layer 8 to the n-GaN layer 4.

On the p-contact layer 11 in the ridge portion,
A p-electrode 12 made of Ni with a thickness of 500 ° is formed, and an exposed surface of the n-GaN layer 4 has a thickness of 500 ° on the exposed surface.
Electrode 13 made of Ti and 5000 ° thick Al
Are formed.

In this semiconductor laser device, the distribution of the refractive index occurs in the horizontal direction of the MQW light emitting layer 7 due to the formation of the ridge portion, and the current is confined in the ridge portion.
By utilizing such a distribution of the refractive index and the constriction of the current, confinement of light in a horizontal direction, that is, control of a transverse mode is performed.

Next, a method of manufacturing the GaN-based semiconductor laser device having the ridge waveguide structure shown in FIG. 1 will be described with reference to FIGS.
The process will be described with reference to the cross-sectional views of FIG.

First, as shown in FIG. 3A, a buffer layer 2, a GaN layer 3, an n-GaN layer 4, an n-GaN layer 4 are formed on a sapphire substrate 1 by MOCVD (metal organic chemical vapor deposition). -Crack preventing layer 5, n- first cladding layer 6, M
QW light emitting layer 7, p-second cladding layer 8, p-low temperature growth layer 9, p-third cladding layer 10, and p-contact layer 1
1 are successively grown.

Incidentally, the thickness of the p-second cladding layer 8 is set to 0.1 mm from the viewpoint of controlling the transverse mode in the semiconductor laser device.
It is preferable that the thickness be in the range of 0.05 to 0.3 μm.

The substrate temperature during growth of the buffer layer 2 is 600
° C, and the substrate temperature during growth of the MQW light emitting layer 7 is 800 ° C.
And The buffer layer 2, the MQW light emitting layer 7, and the p
The substrate temperature during growth of each of the layers 3 to 6, 8, 10, and 11 except the low-temperature growth layer 9 is 1050 ° C., and the substrate temperature during growth of the p-low-temperature growth layer 9 is 600 to 750 ° C. As a result, the layers 2 to 8, 10, and 11 except the p-low temperature growth layer 9 become transparent, while the p-low temperature growth layer 9 is opaque and black. When the p-low temperature growth layer 9 is grown at the substrate temperature or higher, the p-low temperature growth layer 9 becomes transparent.

Next, as shown in FIG. 3 (b), a striped Ni mask 16 is formed in a striped region on the p-contact layer 11, and this is used to perform RIE (reactive ion The p-contact layer 11, the p-third cladding layer 10, and the p-low temperature growth layer 9 are etched by an etching method or a RIBE method (reactive ion beam etching method). Thus, a ridge portion is formed.

In the above-mentioned etching, the p-low temperature growth layer 9 is used as a marker for stopping the etching (etching marker layer). In other words, the semiconductor wafer surface appears opaque when the opaque p-low-temperature growth layer 9 is present in portions other than the Ni mask 16, but when the opaque p-low-temperature growth layer 9 is removed by etching, the semiconductor wafer surface is removed. Changes to transparent. If the etching is stopped when such a change in the color of the surface of the semiconductor wafer is visually confirmed, the p-contact layer 11, the p-third cladding layer 10, and the p-low-temperature growth layer 9 other than the Ni mask 16 are removed. Can be accurately removed.

Subsequently, after the Ni mask 16 is removed, as shown in FIG. 4C, the p-second cladding layer 8 and the p-second cladding layer 8 are removed except for a predetermined region on the p-second cladding layer 8. A Ni mask 17 is formed on the contact layer 11. Using the Ni mask 17, the n-Ga
A part of the region up to the N layer 4 is removed by etching by RIE or RIBE to expose the n-GaN layer 4.

After the above etching, the Ni mask 17 is removed, and the p-contact layer 1 is removed as shown in FIG.
1 except for the upper surface of the ridge portion and the upper surface of the flat portion of the cladding layer,
From the upper surface of the GaN layer 4 and the p-second cladding layer 8 to n-
EB method (electron beam evaporation method) on the side up to the GaN layer 4
Alternatively, the SiO ₂ film 1 is formed by CVD (chemical vapor deposition).
4 is formed.

Further, as shown in FIG. 1, a p-electrode 12 is formed on the exposed surface of the p-contact layer 11, and the n-G
An n-electrode 13 is formed on the exposed surface of the aN layer 4. Finally, the cavity facet is formed by cleaving the sapphire substrate 1 on the {1-100} plane.

In the method of manufacturing the semiconductor laser device according to the present embodiment, the opaque p-low-temperature growth layer 9 is used as a marker for stopping the etching when forming the ridge portion by etching. Good control becomes possible. Since the thickness of the p-second cladding layer 8 greatly affects the lateral mode control of the semiconductor laser device, the reproducibility of the device characteristics of the semiconductor laser device can be improved by controlling the etching depth accurately. At the same time, it is possible to suppress variations in element characteristics between elements.

In the above embodiment, the sapphire substrate 1 is used as the insulating substrate, and the SiO ₂ film 14 is used as the current blocking layer.
A C substrate, a spinel substrate, or the like may be used, and an insulating film other than the SiO ₂ film 14 or an n-type semiconductor layer may be used as the current blocking layer.

Further, in the above embodiment, the opaque p-low temperature growth layer 9 is used as a marker for stopping the etching at the time of etching when forming the ridge portion.
InGaP opaque during etching of parts other than the ridge
It is also possible to use a low-temperature growth layer made of N as an etching marker layer.

For example, when a part of the region from the second cladding layer 8 to the n-crack preventing layer 5 is removed by etching, the n-crack preventing layer 5 made of n-InGaN is used as an etching marker layer. In this case, the n-crack prevention layer 5 is grown at a substrate temperature of 600 to 750 ° C. Since the n-crack prevention layer 5 thus grown is opaque and black, it can be used as a marker for stopping etching.

FIG. 5 is a graph showing Ga in the second embodiment of the present invention.
It is sectional drawing which shows the structure of an N-type semiconductor laser element.

The semiconductor laser device shown in FIG. 5 is a semiconductor laser device having a self-aligned structure. Note that Si is used as an n-type dopant in each layer in FIG. 5, and Mg is used as a p-type dopant.

On the c-plane of the sapphire substrate 21, a buffer layer 22 of undoped Al _0.5 Ga _0.5 N having a thickness of 300 °, an undoped GaN layer 23 having a thickness of 2 μm, an n-GaN layer 24 having a thickness of 3 μm, and n A _0.1 μm thick n-crack preventing layer 25 made of —In _0.1 Ga _0.9 N;
0.7 μm thick n-first layer made of Al _0.15 Ga _0.85 N
The clad layer 26 and the MQW light emitting layer 27 are formed in order. The structure of the MQW light emitting layer 27 is the same as the structure of the MQW light emitting layer 7 shown in FIG.

On the MQW light emitting layer 27, p-Al _0.15 G
A p-second cladding layer 28 of a _0.85 N having a thickness of 0.2 μm is formed. Further, the p-second cladding layer 2
8 except for a stripe-shaped region having a width of 4 μm
A p-low temperature growth layer 29 made of n _0.1 Ga _0.9 N and having a thickness of 0.05 to _0.1 μm and an n-current block layer 32 made of n-AlGaN and having a thickness of 0.5 μm are formed. Further, p-Al _0.15 is formed on the n-current block layer 32 and the stripe-shaped region of the p-second cladding layer 28.
A 0.4 μm thick p-third cladding layer 30 made of Ga _0.85 N and a 0.2 μm thick p-GaN made of p-GaN
Contact layers 31 are formed in order.

Part of the region from the p-contact layer 31 to the n-crack preventing layer 25 has been removed by etching, exposing the n-GaN layer 24.

Further, on the p-contact layer 31, a p-electrode 12 made of Ni having a thickness of 5000 ° is formed.
-The exposed surface of the GaN layer 24 has a T
An n-electrode 13 made of i and 5000 .ANG. thick Al is formed.

In this semiconductor laser device, the current is confined in the striped region between the n-current blocking layers 32, and an optical waveguide is formed in the MQW light emitting layer 27 below the striped region.

Next, a method of manufacturing the GaN-based semiconductor laser device having the self-aligned structure shown in FIG. 5 will be described with reference to the process sectional views of FIG. 6 and FIG.

First, as shown in FIG. 6A, a buffer layer 22, a GaN layer 23 and an n-G layer are formed on a sapphire substrate 21 by MOCVD (metal organic chemical vapor deposition).
aN layer 24, n-crack prevention layer 25, n-first cladding layer 26, MQW light emitting layer 27, p-second cladding layer 2
8, p-low temperature growth layer 29 and n-current blocking layer 32
Are sequentially and continuously grown.

The thickness of the p-second cladding layer 28 is
From the point of control of the transverse mode in the semiconductor laser device,
Preferably, it is in the range of 0.1 to 0.4 μm.

The substrate temperature during growth of the buffer layer 22 is 60
0 ° C., and the substrate temperature during growth of each of the layers 23 to 28 and 32 except for the buffer layer 22 and the p-low temperature growth layer 29 was 105 ° C.
0 ° C., and the substrate temperature during the growth of the p-low temperature growth layer 29 is 6
00 to 750 ° C. Thereby, the p-low temperature growth layer 2
The layers 22 to 28 and 32 except 9 become transparent, and the p-low temperature growth layer 29 is opaque and black. When the p-low temperature growth layer 29 is grown at the substrate temperature or higher, p
The low temperature growth layer 29 becomes transparent.

Subsequently, as shown in FIG. 6B, except for the striped region on the n-current block layer 32, n
Forming the Ni mask 16 on the current blocking layer 32 and using the Ni mask 16 by the RIE method (reactive ion etching method) or the RIBE method (reactive ion beam etching method) to form the n-current blocking layer 32 and the p-low temperature Growth layer 29
Is etched.

In the above etching, the p-low temperature growth layer 29 is used as a marker for stopping the etching (etching marker layer). In other words, the semiconductor wafer surface appears opaque when the opaque p-low-temperature growth layer 29 is present in portions other than the Ni mask 16, but when the opaque p-low-temperature growth layer 29 is removed by etching, the semiconductor wafer surface is removed. Changes to transparent. If the etching is stopped when such a change in the color of the semiconductor wafer surface is confirmed, the p-low temperature growth layer 29 and the n-current block layer 32 other than the Ni mask 16 can be accurately removed. .

In a semiconductor laser device having a self-aligned structure, since the region of the opaque p-low temperature growth layer 29 which is removed by etching is narrow, it is difficult to visually confirm a change in color on the surface of the semiconductor wafer. It is. For this reason, a change in the color of the surface of the semiconductor wafer is confirmed using a microscope.

Subsequently, after the Ni mask 16 is removed, as shown in FIG.
The p-third cladding layer 30 and the p-contact layer 31 are successively grown at a substrate temperature of 1050 ° C. on the upper and striped regions of the p-second cladding layer 28 in this order.

Next, as shown in FIG. 7D, after a Ni mask 17 is formed in a predetermined region on the p-contact layer 31, the Ni mask 17 is used to remove the n-crack preventing layer from the p-contact layer 31. RIE or RIB for some areas up to 25
The n-GaN layer 24 is exposed by being removed by etching using the E method.

After the above-described etching, the Ni mask 17 is removed, and as shown in FIG. 5, the p-electrode 12 is formed on the p-contact layer 31, and the n-electrode 13 is formed on the exposed surface of the n-GaN layer 24. To form Finally, the sapphire substrate 21
Is cleaved on the {1-100} plane to form a resonator end face.

In the method of manufacturing a semiconductor laser device according to the present embodiment, the opaque p-low-temperature growth layer 29 is used as a marker for stopping etching when forming an optical waveguide by etching. It becomes possible to control well. As described above, by controlling the etching depth with high accuracy, the reproducibility of the device characteristics of the semiconductor laser device can be improved, and variations in device characteristics between devices can be suppressed.

In the above embodiment, the sapphire substrate 21 was used as the insulating substrate.
A SiC substrate, a spinel substrate, or the like may be used.

Further, in the above embodiment, the opaque p-low temperature growth layer 29 is used as a marker for stopping the etching at the time of etching at the time of forming the optical waveguide, but it is opaque at the time of etching other parts than the optical waveguide. In
It is also possible to use a low-temperature growth layer made of GaN as an etching marker layer.

For example, when a partial region from the p-contact layer 31 to the n-crack preventing layer 25 is removed by etching, the n-crack preventing layer 25 made of n-InGaN is used as an etching marker layer. In this case, the n-crack prevention layer 25 has a substrate temperature of 600 to 750.
Grow at ° C. Since the n-crack prevention layer 25 thus grown is opaque and black, it can be used as a marker for stopping etching.

Although the first and second embodiments have described the case where the present invention is applied to a semiconductor laser device, the present invention relates to other semiconductor light emitting devices such as a light emitting diode using a GaN-based semiconductor. And other semiconductor elements.

[Brief description of the drawings]

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

FIG. 2 is an energy band diagram showing a structure of an MQW light emitting layer.

FIG. 3 is a first diagram illustrating a method of manufacturing the semiconductor laser device of FIG. 1;
FIG.

FIG. 4 is a second view illustrating a method for manufacturing the semiconductor laser device of FIG. 1;
FIG.

FIG. 5 is a sectional view showing the structure of a semiconductor laser device according to a second embodiment of the present invention.

FIG. 6 is a first diagram illustrating a method of manufacturing the semiconductor laser device of FIG. 2;
FIG.

FIG. 7 is a second view illustrating a method for manufacturing the semiconductor laser device of FIG. 2;
FIG.

[Explanation of symbols]

1,21 sapphire substrate 2,22 buffer layer 3,23 GaN layer 4,24 n-GaN layer 5,25 n-crack prevention layer 6,26 n-first cladding layer 7,27 MQW light emitting layer 8,28 p- the second cladding layer 9, 29 p-low temperature growth layer 10, 30 p-third cladding layer 11 and 31 p-contact layer 12 p electrode 13 n electrode 14 SiO ₂ film 32 n-current blocking layer

Claims (7)

[Claims] An opaque etching marker layer and at least one of gallium, aluminum and indium are formed in a predetermined region on a transparent first nitride-based semiconductor layer containing at least one of gallium, aluminum and indium.
And a transparent second nitride-based semiconductor layer comprising: 2. A method according to claim 1, wherein the first cladding layer is made of a transparent nitride semiconductor containing at least one of gallium, aluminum and indium. The first cladding layer is made of a transparent nitride semiconductor containing at least one of gallium, aluminum and indium. And a second cladding layer made of a transparent nitride-based semiconductor containing at least one of gallium, aluminum and indium, are sequentially formed, and an opaque region is formed in a stripe region on the second cladding layer. And a third cladding layer made of a transparent nitride-based semiconductor containing at least one of gallium, aluminum, and indium. 3. A transparent nitride-based semiconductor containing at least one of gallium, aluminum and indium on a first cladding layer made of a transparent nitride-based semiconductor containing at least one of gallium, aluminum and indium. And a second cladding layer made of a transparent nitride-based semiconductor containing at least one of gallium, aluminum and indium, which is formed in this order, excluding a stripe-shaped region on the second cladding layer. An opaque etching marker layer and a transparent current blocking layer are sequentially formed thereon, and a third cladding layer made of a transparent nitride-based semiconductor containing at least one of gallium, aluminum and indium on the stripe-shaped region. A semiconductor light-emitting device, characterized by forming: 4. An opaque etching marker layer is formed in a predetermined region on a transparent first nitride-based semiconductor layer containing at least one of gallium, aluminum, and indium, and includes a light emitting layer on the etching marker layer. A transparent second nitride-based semiconductor layer containing at least one of gallium, aluminum, and indium is formed; a first electrode is formed on the first nitride-based semiconductor layer; A semiconductor light-emitting device wherein a second electrode is formed on a nitride-based semiconductor layer. 5. The etching marker layer has a thickness of 600 to 75.
The semiconductor light emitting device according to any one of claims 2 to 4, wherein the semiconductor light emitting device is a nitride-based semiconductor layer containing gallium and indium grown at 0 ° C. 6. A step of forming a transparent first nitride-based semiconductor layer containing at least one of gallium, aluminum, and indium; and forming an opaque etching marker layer on the first nitride-based semiconductor layer. Forming a transparent second nitride-based semiconductor layer containing at least one of gallium, aluminum, and indium on the etching marker layer; and forming the second nitride-based semiconductor layer and the etching marker on the etching marker layer. Removing a predetermined region of the layer by etching. 7. The etching marker layer is a nitride-based semiconductor layer containing gallium and indium, and the growth temperature of the etching marker layer is set lower than the growth temperatures of the first and second nitride-based semiconductor layers. 7. The method for manufacturing a semiconductor device according to claim 6, wherein: