JP2000164964A - Manufacture of semiconductor laser system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To carry out a test for a plurality of semiconductor laser elements on a substrate. SOLUTION: Each layer from an electrode layer 117 to an etching layer 112 excepting a semiconductor substrate 110, an electrode layer 118, and a buffer layer 11 is selectively etched, and the etching layer 112 is etched faster than a laser structure layer to from an overhung part 120 of the laser structure layer on a buffer layer 111. Then, stress is applied using a cantilever 130 in the thickness direction 131 on a p-type electrode 119 toward a clad layer 113 so as to make a cleavage in the thickness direction in all layers from the electrode layer 117 to the clad layer 113 to form a reflective mirror on a cleavage face 132. Then, a plurality of laser elements 140 are obtained in an unseparated state on a semiconductor substrate 110 for carrying out an operation test for each laser elements 140. The semiconductor substrate 110 is scribed by a scriber 133, to cut the semiconductor substrate 110 in the thickness direction to obtain a plurality of laser elements 140.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a method for manufacturing a semiconductor laser device.

[0002]

2. Description of the Related Art In manufacturing a conventional semiconductor laser device, a method of cleaving a semiconductor layer including a substrate in a thickness direction has been adopted in order to manufacture a reflection mirror which is a component of a resonator.

[0003]

However, since a method of cleaving a semiconductor layer including a substrate in a thickness direction is used to manufacture a reflection mirror, a single semiconductor laser device separated by cleavage is used. There was a problem that it had to be tested individually.

[0004] An object of the present invention is to solve the above problems,
It is an object of the present invention to provide a method of manufacturing a semiconductor laser device capable of testing a plurality of semiconductor laser elements on a substrate.

[0005]

According to the present invention, there is provided a method of manufacturing a semiconductor laser device, comprising the steps of: forming an etching layer on a semiconductor substrate; forming a laser structure layer on the etching layer; Forming an electrode layer on the layer and on the back surface of the semiconductor substrate, separating the at least the laser structure layer into units of a laser element, and etching an etching solution for etching the etching layer faster than the laser structure layer. Forming an overhang portion in the laser structure layer by etching using the method; cleaving the overhang portion of the laser structure layer to form a reflection mirror in the laser structure layer; A plurality of laser elements formed on the semiconductor substrate are not separated from the semiconductor substrate. Characterized in that it comprises a step of performing an operation test individually, and separating by the semiconductor substrate is cut for each of the respective laser elements.

Here, in the method of manufacturing a semiconductor laser device, the step of forming the laser structure layer includes, for example, sequentially forming an etching layer, a cladding layer, an active layer, a cladding layer, and a contact layer on the etching layer. This forms the laser structure layer.

[0007]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing a first embodiment of the present invention;

<First Embodiment> FIG. 1 is a sectional view taken along a plane parallel to a cleavage plane, showing a structure of a completed semiconductor laser device according to a first embodiment of the prior art leading to the present invention. 2 to 4 are cross-sectional views showing first to third steps of the method for manufacturing the semiconductor laser device of FIG. 1 along a plane orthogonal to the cleavage plane.

The semiconductor laser device according to this embodiment is constituted by using a semiconductor light emitting element. As shown in FIG. 3, the buffer layer 11 and the active layer 14 except for the sapphire substrate 10 are selectively etched. 10
After forming a space between the active layer 14 and the p-type electrode 17
A predetermined stress is applied to the active layer 14 from above in the thickness direction 19 using the cantilever 19, and the active layer 14 excluding the sapphire substrate 10 and the buffer layer 11 is cleaved in the thickness direction. It is characterized in that a reflection mirror is formed.

[0010] The method of manufacturing the semiconductor laser device of the present embodiment.
The process will be described in detail below with reference to FIGS. 2 to 4 and FIG.
I will tell. In FIG. 1 and FIG.
On a semi-insulating sapphire substrate 10 having a thickness of 0 μm,
Each single crystal semiconductor crystal is grown using a
The layers are sequentially grown as follows. (1) First, in order to suppress the generation of crystal defects, A
The buffer layer 11 made of lGaN is grown to a thickness of 5 μm.
I do. During the growth, a GaN / AlN superlattice structure
Forming an intrinsic semiconductor layer,_TwoBy department
By providing a separate mask, lateral crystal growth can be improved.
May be used to further suppress the occurrence of crystal defects. (2) Next, an n-type impurity ion made of Si
Injection volume 10¹⁸/ Cm^ThreeN injected only⁺Type GaN
The contact layer 12 is grown to a thickness of 2 μm. This
The contact layer 12 is partially removed before cleavage. (3) Further, the n-type impurity ions made of Si
Injection volume 5 × 10¹⁷/ Cm ^ThreeN-type GaN implanted only
The cladding layer 13 is grown to a thickness of 2 μm. (4) Non-doped GaN to be an intrinsic semiconductor i-layer
The active layer 14 is grown to a thickness of 2000. (5) Next, a p-type impurity ion made of Mg is, for example,
Injection volume 5 × 10¹⁷/ Cm ^ThreeP-type AlGa implanted only
N, and the thickness of the cladding layer 15 as a hole injection layer is
Grow by 2 μm. (6) Further, for example, p-type impurity ions of Mg
Injection volume 10¹⁸/ Cm^ThreeP injected only⁺Type GaN
A contact layer 16 is grown to a thickness of 500 °.

(7) After the crystal growth, a strip-shaped p-type electrode 17 having a width w _p and a length l _p is formed on the contact layer 16, and unnecessary portions are removed by mesa etching to form a mesa. after forming the part, as shown in FIG. 1, to form an n-type electrode 18 having a width w _n on the contact layer 12.

Further, the following steps are performed in order to fabricate the reflecting mirror surface of the semiconductor laser device by cleavage. (8) As shown in FIG. 2, the periphery of the mesa portion is removed by reactive ion etching. I do. At this time, the p-type electrode 17 including the active layer 14 is
The side surface of the mesa portion up to this is an uneven surface as shown in FIG. (9) Next, the buffer layer 11 is oxidized by about 20 μm from the edge portion by a thermal oxidation step. (10) Further, as shown in FIG. 3, the oxidized buffer layer 11 is selectively etched and removed using a wet etching method. As a result, the length of the buffer layer 11 in the mesa portion in the longitudinal direction becomes shorter than the length of the active layer 14 in the longitudinal direction. The sapphire substrate 10 is separated. (11) While viewing the element in this state using a microscope, the thickness direction (stress application direction) 1
At 9d, by applying a predetermined stress to the floating active layer 14 from above the p-type electrode 17, the p-type electrode 17 including the active layer 14 is removed from the cladding layer 13 as shown in FIG. Only the mesa portion up to can be cleaved. This cleavage is performed on both sides in the longitudinal direction of the mesa portion to form a pair of reflecting mirror surfaces facing each other.
Here, the pair of mirror surfaces formed by cleavage have no unevenness and have extremely good light reflection characteristics.

By injecting carriers by applying a DC reverse bias voltage using, for example, a DC power supply to the semiconductor light emitting device configured as described above, light emission occurs in the active layer 14 and the obtained light is Light confinement occurs between the cladding layers 13 and 15 located above and below the active layer 14. Light confinement occurs between the strip-shaped p-type electrode 17 and the sapphire substrate 10 in the vertical direction of the element due to an increase in the refractive index due to current injection. In the direction parallel to the strip-shaped p-type electrode 17, the cleavage mirror formed by the pair of opposed cleavage planes described above becomes a reflection mirror, and optical amplification by laser oscillation occurs. Light emitted by the laser oscillation is emitted from a side surface in a direction perpendicular to the direction of light reflection by the pair of reflecting mirrors.

As described above, according to the present embodiment, as shown in FIG. 3, the buffer layer 11 and the active layer 14 excluding the sapphire substrate 10 are selectively etched to thereby form the sapphire substrate 10 and the active layer 14. After a space is formed between the sapphire substrate 10 and the buffer layer 11, a predetermined stress is applied in the thickness direction 19 d from above the p-type electrode 17 toward the active layer 14 using the cantilever 19.
The reflection mirror is formed on the cleavage plane by cleaving the active layer 14 excluding the above in the thickness direction. Therefore, in the past, cleavage was performed from the sapphire substrate 10 in order to fabricate a reflection mirror. However, by providing a space between the active layer 14 and the sapphire substrate 10, only the Can be cleaved. Therefore, the cavity mirror surface of the GaN-based semiconductor laser device, which has been difficult in the past, has better light reflection characteristics as compared with the conventional example, and can be easily manufactured with a simpler process than the conventional example. Can be manufactured.

Further, a plurality of device devices can be formed on one sapphire substrate 10 without cutting the sapphire substrate 10.
A light emission operation test can be performed on all the above element devices at once. As a result, the efficiency of the test is improved, and only the devices that pass the test can be selected and cut, so that the yield of the element devices can be significantly improved. In addition,
Test costs and manufacturing costs can be significantly reduced.

<Second Embodiment> FIG. 5 is a sectional view taken along a plane parallel to a cleavage plane showing a structure of a completed semiconductor laser device according to a second embodiment of the prior art leading to the present invention. 6 to 8 are cross-sectional views showing the first to third steps of the method for manufacturing the semiconductor laser device of FIG. 5 along a plane orthogonal to the cleavage plane.

The semiconductor laser device of this embodiment is constituted by using a semiconductor light emitting element. As shown in FIG. 7, the semiconductor substrate 20 is selectively etched by excluding the buffer layer 21 and the active layer 23 except for the semiconductor substrate 20. After a space is formed between the semiconductor substrate 20 and the active layer 23, a predetermined stress is applied in the thickness direction 28 d from above the p-type electrode 27 toward the active layer 23 using the cantilever 28. It is characterized in that a reflection mirror is formed on a cleavage plane by cleaving the active layer 23 excluding the layer 21 in the thickness direction.

A method for manufacturing the semiconductor laser device according to the present embodiment.
Will be described in detail below with reference to FIGS. 6 to 8 and FIG.
I will tell. 5 and 6, first, n formed of Si is used.
Type impurity ions are, for example, implanted amount 10¹⁸/ Cm^ThreeJust injection
Done n⁺300μm thick semi-insulating GaAs
Using an epitaxial growth apparatus on the conductive semiconductor substrate 20
Then, the growth of each layer of the single crystal semiconductor crystal is sequentially performed as follows.
Do. (1) First, in order to suppress the generation of crystal defects, S
The n-type impurity ion i¹⁸/ C
m^ThreeN injected only⁺Type buffer made of AlGaAs
Layer 21 is grown to a thickness of 3 μm. (2) Next, an n-type impurity ion made of Si
Injection volume 5 × 10¹⁷/ Cm ^ThreeImplanted n-type GaAs
Is grown to a thickness of 3 μm. (3) Non-doped GaAs to be an intrinsic semiconductor i-layer
The active layer 23 is grown to a thickness of 200 nm. (4) Next, the p-type impurity ions of Be
Injection volume 5 × 10¹⁷/ Cm ^ThreeP-type AlGa implanted only
The cladding layer 24 serving as a hole injection layer is made of As.
Grow by 1500 nm. (5) Further, the p-type impurity ions of Be
Injection volume 10¹⁸/ Cm^ThreeP injected only⁺Type GaAs
A contact layer 25 is grown to a thickness of 200.

(6) After the crystal growth, a strip-shaped p-type electrode 27 having a width w _p and a length l _p is formed on the contact layer 25, and unnecessary portions are removed by mesa etching to form a mesa. While forming the portion, the n-type electrode 26 is formed on the back surface of the semiconductor substrate 20.

Further, the following steps are performed in order to fabricate the reflection mirror surface of the semiconductor laser device by cleavage. (7) As shown in FIG. 6, the periphery of the mesa is removed by etching using a reactive ion etching method. I do. At this time, the p-type electrode 27 including the active layer 23 is
The side surface of the mesa portion up to this is an uneven surface as shown in FIG. (8) Next, the buffer layer 21 is oxidized by about 20 μm from the edge portion by a thermal oxidation step. (9) Further, as shown in FIG. 7, the oxidized buffer layer 21 is selectively etched and removed using a wet etching method. As a result, the length of the buffer layer 21 in the mesa portion in the longitudinal direction becomes shorter than the length of the active layer 23 in the longitudinal direction.
A part of 2, 24, 25, 27 and the semiconductor substrate 20 are separated. (10) While viewing the element in this state using a microscope, the thickness direction (stress application direction) 2 is
At 8d, by applying a predetermined stress to the floating active layer 23 from above the p-type electrode 27, only the mesa portion from the p-type electrode 27 including the active layer 23 to the cladding layer 22 can be easily formed. Can be cleaved. This cleavage is performed on both sides of the mesa portion in the longitudinal direction, and the cleavage is performed on one side facing each other.
A pair of reflecting mirror surfaces are formed. Here, 1
The mirror surfaces of the pair have very good light reflection characteristics without unevenness.

By applying a DC reverse bias voltage to the semiconductor light emitting device configured as described above using, for example, a DC power supply and injecting carriers, light emission occurs in the active layer 23, and the obtained light is Light confinement occurs between the cladding layers 22 and 24 located above and below the active layer 23. Light confinement occurs between the strip-shaped p-type electrode 27 and the semiconductor substrate 20 in a direction perpendicular to the element due to a rise in the refractive index due to current injection. In the direction parallel to the strip-shaped p-type electrode 27, the cleavage mirror formed by the pair of opposed cleavage planes described above serves as a reflection mirror, and optical amplification by laser oscillation occurs. Light emitted by the laser oscillation is emitted from a side surface in a direction perpendicular to the direction of light reflection by the pair of reflecting mirrors.

As described above, according to the present embodiment, as shown in FIG. 7, by selectively etching the buffer layer 21 and the active layer 23 except for the semiconductor substrate 20, the semiconductor substrate 20 and the active layer 23 are selectively etched. Then, a predetermined stress is applied to the active layer 23 from above the p-type electrode 27 toward the active layer 23 in the thickness direction 28d using the cantilever 28, and the active layer excluding the semiconductor substrate 20 and the buffer layer 21 is removed. A reflection mirror is formed on the cleavage plane by cleaving the layer 23 in the thickness direction. Accordingly, the active layer 23 has been conventionally cleaved from the semiconductor substrate 20 in order to manufacture a reflection mirror.
By providing a space between the semiconductor substrate 20 and the semiconductor substrate 20, only the active layer 23 can be cleaved while the semiconductor substrate 20 remains. Therefore, the resonator mirror surface of the semiconductor laser device has better light reflection characteristics as compared with the conventional example, and can be easily manufactured by a simpler process than the conventional example.

Further, since a plurality of device devices can be formed on one semiconductor substrate 20 wafer without cutting the wafer, the light emitting operation of all the device devices on the semiconductor substrate 20 can be performed. Tests can be performed at once. As a result, the efficiency of the test is improved, and only the devices that pass the test can be selected and cut, so that the yield of the element devices can be significantly improved. As described above, the test cost and the manufacturing cost can be significantly reduced.

<Third Embodiment> FIGS. 9 to 13 are cross-sectional views taken along a plane orthogonal to a cleavage plane showing respective steps of a method of manufacturing a semiconductor laser device according to a third embodiment of the present invention. FIG.

The semiconductor laser device of this embodiment is constituted by using a semiconductor light emitting element. As shown in FIG. 11, the semiconductor laser device from the electrode layer 117 excluding the semiconductor substrate 110, the electrode layer 118 and the buffer layer 111 to the etching layer 112 By selectively etching each layer and selectively etching the etching layer 112 faster than the laser structure layer located above the cladding layer 113, the buffer layer 11
After forming an overhang portion 120 of the laser structure layer composed of a layer group from the electrode layer 117 to the cladding layer 115 on the first electrode 1, as shown in FIG. A predetermined stress is applied in the thickness direction 131 using the cantilever 130, and the electrode layer 117 is applied.
By cleaving each layer from the first to the cladding layer 113 in the thickness direction, a reflection mirror is formed on the cleavage plane 132 to obtain a plurality of laser elements 140 without being separated on the semiconductor substrate 110. A test is performed, and then, as shown in FIG. 13, the semiconductor substrate 110 is scribed by using a scriber 133 to cut the semiconductor substrate 110 in the thickness direction, thereby forming a plurality of laser elements 140.
It is characterized by obtaining.

A method of manufacturing the semiconductor laser device according to this embodiment will be described below in detail with reference to FIGS.

As shown in FIG. 9, a buffer layer 111 for suppressing the occurrence of crystal defects is formed on a semiconductor substrate 110 made of, for example, GaAs by epitaxial growth. This buffer layer 111 has a thickness of about 5 μm.
And an n-type impurity of, for example, Si is 3 × 10 ¹⁸ / c
It is made of GaAs implanted with a doping amount of about m ³ . Next, an etching layer 12 of AlGaAs having a thickness of about 1 μm is formed on the buffer layer 111 by epitaxial growth. This etching layer 12 is made of Al
Rich, that is, specifically, when Al is 0.7
In the order of magnitude, the remaining composition is comprised in the order of magnitude of 0.3. This etching layer 112 is also used for the buffer layer 1.
11, an n-type impurity made of, for example, Si is 3 ×
It is implanted with a doping amount of about 10 ¹⁸ / cm ³ .

Next, in FIG. 9, a laser structure layer is formed on the surface of the etching layer 112. In particular,
On the surface of the etching layer 112, a cladding layer 113 made of n-type GaAs in which, for example, Si as an n-type impurity is doped at a doping amount of about 1 × 10 ¹⁸ / cm ^3, has a thickness of about 2 μm.
m. Next, on the surface of the cladding layer 113, about 5 × 10 ¹⁷ / c Be as a p-type impurity is deposited.
An active layer 114 made of GaAs doped with an amount of m ³ and having a thickness of about 2000 ° is grown. Then
Be as a p-type impurity is 1 × on this active layer 114.
P-type AlG implanted with a doping amount of about 10 ¹⁷ / cm ³
An aAs cladding layer 115 is grown to a thickness of about 2 μm. The cladding layer 115 functions as a hole injection layer. Further, p such as Be is formed on the cladding layer 115.
A p ⁺ -type GaAs contact layer 116 is implanted in a large amount with a doping amount of about 5 × 10 ¹⁸ / cm ³ and grown to a thickness of about 500 °. Lastly, the Pt / Ti / Au which has made ohmic contact with the contact layer 116
Is formed, and an n-type electrode layer 118 made of AuGe / Ni / Au is also formed on the back surface of the semiconductor substrate 110.

The next step is, as shown in FIG.
Type electrode layer 117, contact layer 116, cladding layer 11
5. A laser element 1 having a layer group including an active layer 114, a cladding layer 113, and an etching layer 112 as a laser structure layer.
It is characterized by being separated by etching into 40 units.
The unit of the laser element 140 here has a rectangular shape in which the length Lp of one side in the horizontal direction is about 300 to 600 μm, and the distance Ld between the elements is about 10 μm. More specifically, this etching step will be described. The electrode layer 117 is partitioned and separated in advance for each laser element 140 using a well-known lift-off technique, and the p-type electrode 11 is formed.
After that, for example, sulfuric acid: 1, hydrogen peroxide: 8, water: 8
The layer group of the laser structure layer (contact layer 116, clad layer 115,
Active layer 114, cladding layer 113 and etching layer 11
2) is selectively etched. Therefore, the buffer layer 111 is not etched here.

Next, as shown in FIG. 11, an etching solution for etching the etching layer 112 faster than the respective layers 113 to 116 of the laser structure layer other than the etching layer 112, specifically, for example, hydrofluoric acid: 95cc,
The etching layer 112 is formed using a hydrofluoric acid-based etchant having a composition such as ammonia fluoride: 120 g and water: 300 cc.
Is etched faster than the other layers 113 to 116 so that the portions of the other layers 113 to 116 have an eaves-like shape, and the laser structure layer projecting over the semiconductor substrate 110 and the buffer layer 111 is overlaid. The hang portion 120 is formed on the buffer layer 111. Here, the buffer layer 1 is located immediately below the overhang portion 120.
A space is formed between 11 and the cladding layer 113. The horizontal length Lr of the overhang portion of the overhang 120 is, for example, about 10 μm.

Next, as shown in FIG. 12, a predetermined stress is applied to the semiconductor substrate 110 in the thickness direction 131 from the surface of the electrode layer 117 to the overhang portion 120 by using a microprobe 130 or the like. By cleaving a layer group of the laser structure layer including the electrode layer 117, the contact layer 116, the cladding layer 115, the active layer 114, and the cladding layer 113 on which the overhang portion 120 is formed, cleavage planes on both side surfaces of the active layer 114 A reflection mirror is formed on 132, and a plurality of laser elements 140 having reflection mirrors on both side surfaces are obtained. The surface of the reflecting mirror formed by this cleavage has no irregularities and exhibits extremely good light reflection characteristics. The cleavage for forming the reflection mirror is performed by applying a predetermined stress in the thickness direction of the semiconductor substrate 110, but may be performed by applying ultrasonic waves to the entire semiconductor substrate 110, for example.

Although a large number of laser elements 140 are formed on the semiconductor substrate 110 in this manner, not all of them are non-defective products that emit laser light. Therefore, each laser element 140 is not separated from the semiconductor substrate 110. The p-type electrode 119 and the n-type electrode layer 118 of each laser element 140
Perform an operation test by applying a predetermined DC voltage between
The non-defective product and the defective product as the laser element 140 are selected, and for example, a red paint is applied to the defective product so as to be easily identified.

In the last step, as shown in FIG. 13, a large number of laser elements 140 on the semiconductor substrate 110, which have been checked for operation, are removed from the semiconductor substrate 1 as shown in FIG.
The surface of the buffer layer 111 on the substrate 10 is scribed using a scriber 133 so that each laser element 140
Separate each time. Of the plurality of laser elements 140 separated in this way, the laser element 140 which was determined to be defective in the previous operation test was coated with red paint. 14
Sorting can be performed with 0 as a non-defective product.

In the above embodiment, the semiconductor substrate 110 made of GaAs is used. However, the present invention is not limited to this, and other III-V compounds, ZnSe, ZnS
A semiconductor substrate such as a II / VI compound semiconductor such as PbTe or SnTe or a IV / VI compound semiconductor such as SnTe may be used.

As described above, in the past, the substrate was cleaved from the substrate in order to fabricate a reflection mirror. However, according to the present embodiment, the laser structure layer having the active layer 114 and the semiconductor substrate 110 are cleaved. An overhang portion 120 is formed in the buffer layer 1 immediately below the overhang portion 120.
By providing a space between 11 and the cladding layer 113,
It is possible to cleave only the laser structure layer provided with the active layer 114 while leaving the semiconductor substrate 110. Therefore,
The resonator mirror surface of the semiconductor laser device has good light reflection characteristics as compared with the conventional example, and can be easily manufactured by a simpler process as compared with the conventional example. In addition, 1
A plurality of laser elements 140 on one semiconductor substrate 110,
Since all the laser elements 1 on the semiconductor substrate 110 can be formed without cutting the semiconductor substrate 110,
A light emission operation test can be performed on the light emitting device 40 at a time. As a result, the test execution efficiency is improved, and only the devices that pass the test can be selected and cut, so that the yield of the laser element 140 can be significantly improved. As described above, there is a specific effect that the test cost and the manufacturing cost can be significantly reduced.

<Modification> In the above embodiment, the single crystal semiconductor crystal is grown by the metalorganic vapor phase epitaxy using the epitaxial growth apparatus. However, the present invention is not limited to this. It may be formed by a method or the like.

[0037]

As described above in detail, according to the method of manufacturing a semiconductor laser device according to the present invention, an overhang portion is formed between a laser structure layer having an active layer and a semiconductor substrate. By providing a space directly below the portion and between the buffer layer and the cladding layer, it becomes possible to cleave only the laser structure layer having the active layer while leaving the semiconductor substrate. Therefore, the resonator mirror surface of the semiconductor laser device has better light reflection characteristics as compared with the conventional example, and can be easily manufactured by a simpler process than the conventional example. Further, a plurality of laser elements can be formed on one semiconductor substrate without cutting the semiconductor substrate, so that a light emission operation test can be performed on all the laser elements on the semiconductor substrate at one time.
As a result, the test execution efficiency is improved, and as a result, the manufacturing cost of the semiconductor laser device can be significantly reduced.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view taken along a plane parallel to a cleavage plane, showing a structure of a completed semiconductor laser device according to a first embodiment of the prior art leading to the present invention.

FIG. 2 is a cross-sectional view taken along a plane orthogonal to a cleavage plane, showing a first step in a method for manufacturing the semiconductor laser device of FIG. 1;

FIG. 3 is a cross-sectional view taken along a plane orthogonal to a cleavage plane, showing a second step of the method for manufacturing the semiconductor laser device of FIG. 1;

FIG. 4 is a cross-sectional view taken along a plane orthogonal to a cleavage plane, showing a third step in the method for manufacturing the semiconductor laser device of FIG. 1;

FIG. 5 is a cross-sectional view taken along a plane parallel to a cleavage plane, showing a structure of a completed semiconductor laser device according to a second embodiment of the prior art leading to the present invention.

FIG. 6 is a cross-sectional view, taken along a plane orthogonal to a cleavage plane, showing a first step of the method for manufacturing the semiconductor laser device of FIG. 5;

FIG. 7 is a cross-sectional view, taken along a plane orthogonal to a cleavage plane, showing a second step in the method for manufacturing the semiconductor laser device in FIG. 5;

FIG. 8 is a cross-sectional view taken along a plane orthogonal to a cleavage plane, showing a third step in the method for manufacturing the semiconductor laser device in FIG. 5;

FIG. 9 is a cross-sectional view taken along a plane orthogonal to a cleavage plane, showing a first step in a method for manufacturing a semiconductor laser device according to a third embodiment of the present invention.

FIG. 10 shows a second method of manufacturing the semiconductor laser device of FIG.
FIG. 4 is a cross-sectional view taken along a plane orthogonal to a cleavage plane, showing the step of FIG.

FIG. 11 shows a third method of manufacturing the semiconductor laser device of FIG. 9;
FIG. 4 is a cross-sectional view taken along a plane orthogonal to a cleavage plane, showing the step of FIG.

FIG. 12 shows a fourth method of manufacturing the semiconductor laser device of FIG. 9;
FIG. 4 is a cross-sectional view taken along a plane orthogonal to a cleavage plane, showing the step of FIG.

13 shows a fifth method of manufacturing the semiconductor laser device of FIG. 9;
FIG. 4 is a cross-sectional view taken along a plane orthogonal to a cleavage plane, showing the step of FIG.

[Explanation of symbols]

 Reference Signs List 20: semiconductor substrate, 21: buffer layer, 22: clad layer, 23: active layer, 24: clad layer, 25: contact layer, 26: n-type electrode, 27: p-type electrode, 28: cantilever, 28d: stress Application direction, 28 s cleavage plane, 110 semiconductor substrate, 111 buffer layer, 112 etching layer, 113 cladding layer, 114 active layer, 115 cladding layer, 116 contact layer, 117, 118 electrode layer, 119: p-type electrode, 120: overhang portion, 130: microprobe, 132: cleavage plane, 140: laser element.

 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Chiaki Domoto 5 Sanraya, Inaya, Seika-cho, Soraku-gun, Kyoto Pref. Within ATI Research Institute for Environmentally Adaptable Communications (72) Inventor Norifumi Egami Kyoto 5 Shiragaya, Seiyacho, Seika-cho, Soraku-gun

Claims (2)

[Claims] A step of forming an etching layer on the semiconductor substrate; a step of forming a laser structure layer on the etching layer; and forming an electrode layer on the laser structure layer and on a back surface of the semiconductor substrate, respectively. Forming an overhang portion in the laser structure layer by etching at least a step of separating the laser structure layer into units of a laser element; and etching the etch layer with an etchant that etches faster than the laser structure layer. Cleaving an overhang portion of the laser structure layer to form a reflection mirror on the laser structure layer; and removing the plurality of laser elements formed on the semiconductor substrate through the respective steps to the semiconductor substrate. Performing an operation test individually without separating from the semiconductor substrate; Serial manufacturing method of a semiconductor laser device which comprises a step of separating by cutting each laser element. 2. The method of manufacturing a semiconductor laser device according to claim 1, wherein the step of forming the laser structure layer comprises: forming an etching layer, a cladding layer, an active layer, a cladding layer, and a contact layer on the etching layer. A method for manufacturing a semiconductor laser device, wherein the laser structure layer is formed by sequentially forming the laser structure layer.