JP2000183438A - Manufacture of semiconductor laser - Google Patents

Abstract

PROBLEM TO BE SOLVED: To manufacture at a high yield a semiconductor laser having a substrate of several tens of microns in thickness. SOLUTION: A semiconductor laser wafer 5 is obtained by forming a crystal growth layer 32 and a surface electrode 34 on a semiconductor substrate 31 of several hundreds of microns in thickness, and a semiconductor laser chip 3 is obtained by cleaving the semiconductor laser wafer 5. A heat sink 4 is connected to the side of the crystal growth layer 32 of the semiconductor laser chip 3, and the backside of the substrate 31 is thinned off by several to several tens of microns, until it becomes 5 μm, for example, using a mechanical polishing nethod through etching or sputtering.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a semiconductor laser device, and more particularly, to a method for manufacturing a semiconductor laser device having a thickness of several .mu.
The present invention relates to a method of manufacturing a semiconductor laser device.

[0002]

2. Description of the Related Art Generally, in a high-temperature environment, a semiconductor laser chip is limited in output due to thermal saturation, has a longer oscillation wavelength, and has a COD (Catas
This causes various inconveniences such as a reduction in the generation level of tropical optical damage and a reduction in reliability due to the destruction of the crystal structure.

Therefore, in a laser chip of a high-power semiconductor laser device, the semiconductor laser chip must have a high thermal conductivity in order to prevent the temperature from becoming high due to Joule heat generated from the chip itself during driving and to avoid the above-mentioned disadvantages. It is necessary to release the heat of the semiconductor laser chip by bonding to a heat sink having Therefore, various studies have conventionally been made to achieve high heat dissipation of the semiconductor laser device.

For example, a conventional high-power semiconductor laser device shown in FIG. 17 has a semiconductor substrate 11 having a thickness of 100 μm to 300 μm, a crystal growth layer 12 having a thickness of several μm, and electrodes 13 and 14.
The semiconductor laser chip 1 and the heat sink 2 are bonded via a bonding layer 21. The conductive wire 26 electrically connects the back electrode 13 to another electrode (not shown). The heat sink 2 is cooled by cooling water, a Peltier device, or the like. Crystal growth layer 12
Is formed by sequentially laminating a buffer layer 15, an active layer 16, a cladding layer 17, and a contact layer 18.

The thermal conductivity of the semiconductor substrate 11 is the same as that of the heat sink 2 (150 W / m · K to 390 W).
/ M · K), for example, the thermal conductivity of a GaAs substrate is about 45 W / m · k. Therefore, the heat sink 2 is bonded to the crystal growth layer 12 side (junction down bonding), not the substrate 11 side of the semiconductor laser chip 1, so that heat generated in the active layer 16 is quickly conducted to the heat sink 2. I have.

Conventionally, a semiconductor laser device having such a configuration forms a crystal growth layer 12 and a surface electrode 14 on a single crystal semiconductor substrate wafer, and then attaches a reinforcing material such as a glass plate to the surface of the wafer to form a substrate 11 having a thickness of 100 μm-30
This is obtained by grinding the back surface of the substrate until it reaches 0 μm, then forming the back surface electrode 13 and performing cleavage to obtain the semiconductor laser chip 1 and joining it to the heat sink 2 by soldering or the like.

As shown in FIG. 18, a heat sink 20 and a Peltier element are bonded not only to the crystal growth layer 12 side of the semiconductor laser chip 1 but also to the substrate 11 side to cool the semiconductor laser chip 1 from both upper and lower directions. Is proposed, but the thickness of the substrate 11 is 100 μm to 300 μm.
m, the heat radiation effect from the substrate 11 side is low.

[0008]

In order to further improve the heat radiation of the semiconductor laser chip, it is necessary to reduce the thickness of the semiconductor substrate to several μm to several tens μm and to improve the heat radiation from the substrate side. Although effective, the strength of the substrate is reduced when the thickness of the substrate is several μm to several tens μm, and the strength is insufficient. Problems such as being unable to scribe due to deflection occur.

The present invention has been made to solve the above problems, and has as its object to provide a method for manufacturing a semiconductor laser device having a substrate having a thickness of several μm to several tens μm with high yield.

[0010]

In order to achieve the above object, the present invention provides a process for forming a crystal growth layer on one main surface of a semiconductor substrate and an electrode thereon to obtain a semiconductor laser wafer, Cleaving the semiconductor laser chip to obtain a semiconductor laser chip; bonding a heat sink to the crystal growth layer side of the semiconductor laser chip; and bonding the substrate side of the semiconductor laser chip with the heat sink bonded to the substrate. The thickness is several μm to several tens μm, preferably 5 μm.
thinning to a thickness of μm.

According to the present invention, the heat sink is joined to the crystal growth layer side of the semiconductor laser chip, and in this state, the thickness of the substrate of the semiconductor laser chip is reduced to several μm to several tens μm, preferably 5 μm. Is done.

A second invention provides a process for forming a crystal growth layer on one principal surface of a semiconductor substrate and an electrode thereon to obtain a semiconductor laser wafer, and a method for forming a crystal heat sink wafer on the crystal growth layer side of the semiconductor laser wafer. Joining,
A step of thinning the surface of the semiconductor laser wafer on the substrate side in a state where the heat sink wafer is bonded, until the thickness of the substrate becomes several μm to several tens μm, preferably 5 μm; Cleaving the semiconductor laser wafer together with the heat sink wafer.

According to the present invention, the heat sink wafer is joined to the crystal growth layer side of the semiconductor laser wafer, and in this state, the substrate of the semiconductor laser wafer is thinned to a thickness of several μm to several tens μm, preferably 5 μm. Thereafter, the semiconductor laser wafer and the heat sink wafer are cleaved.

The next invention provides a step of forming a crystal growth layer on one main surface of a semiconductor substrate and an electrode thereon to obtain a semiconductor laser wafer, and mounting a plurality of heat sinks on the crystal growth layer side of the semiconductor laser wafer. Aligning and joining them so that they can be respectively joined to a plurality of chips that can be obtained by cleavage, and joining the heat sink to the substrate-side surface of the semiconductor laser wafer in a state where the heat sink is joined. a step of thinning to a thickness of μm to several tens of μm, preferably 5 μm, and a step of cleaving the thinned semiconductor laser wafer.

According to the present invention, the heat sink is bonded to the crystal growth layer side of the semiconductor laser wafer, and in this state, the substrate of the semiconductor laser wafer is thinned to a thickness of several μm to several tens μm, preferably 5 μm, Thereafter, the semiconductor laser wafer is cleaved.

The next invention is a process for forming a crystal growth layer on one main surface of a semiconductor substrate and an electrode thereon to obtain a semiconductor laser wafer, and a heat sink wafer having a groove on the crystal growth layer side of the semiconductor laser wafer. And aligning the groove so that the groove coincides with the planned cleavage position of the semiconductor laser wafer; and bonding the heat sink wafer to the substrate side surface of the semiconductor laser wafer in a state where the thickness of the substrate is reduced. Several μm to several tens μm, preferably 5 μm
m, and cleaving the thinned semiconductor laser wafer together with the heat sink wafer.

According to the present invention, the heat sink wafer is joined to the crystal growth layer side of the semiconductor laser wafer, and in this state, the substrate of the semiconductor laser wafer is thinned to a thickness of several μm to several tens μm, preferably 5 μm. Thereafter, the semiconductor laser wafer and the heat sink wafer are cleaved.

Each of the above inventions further includes a step of joining a heat sink wafer or a plurality of heat sinks to the substrate side of the thinned semiconductor laser wafer.

According to the present invention, the heat sink wafer is joined to the crystal growth layer side of the semiconductor laser wafer, and in this state, the substrate of the semiconductor laser wafer is thinned to a thickness of several μm to several tens μm, preferably 5 μm. Further, a heat sink wafer or a heat sink is also joined to the substrate side of the semiconductor laser wafer, and thereafter the semiconductor laser wafer is cleaved.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a method for manufacturing a semiconductor laser device according to the present invention will be described below in detail with reference to the accompanying drawings.

Embodiment 1 FIG. 1 is a longitudinal sectional view showing an example of a semiconductor laser device according to the present invention. In this semiconductor laser device, a crystal growth layer 32 and a surface electrode 34 are formed in this order on one main surface of a GaAs semiconductor substrate 31 having a thickness of about several μm to several tens μm, but not particularly limited to, for example, 5 μm. And a semiconductor laser chip 3 having a back electrode 33 formed on the other main surface.

The heat sink 4 is provided to be bonded to the crystal growth layer 32 via the bonding layer 41. The crystal growth layer 32 is formed by stacking a buffer layer 35, an active layer 36, a clad layer 37, and a contact layer 38 in this order from the substrate 31 side. The heat sink 4 is made of Cu, Cu
It is made of a material having high thermal conductivity such as W, W, Mo, Si, diamond or AlN.

Next, a method of manufacturing the semiconductor laser device shown in FIG. 1 will be described with reference to FIGS. 2 and 3 are a schematic diagram and a process diagram showing an example of a manufacturing process of the semiconductor laser device shown in FIG. 1, respectively.

First, a crystal growth layer 32 and a surface electrode 34 (omitted in FIG. 2 on a semiconductor substrate 31 having a thickness of several hundred μm)
1 (see FIG. 1) to obtain a semiconductor laser wafer 5 (FIG. 2A, step S11 in FIG. 3). Subsequently, the semiconductor laser wafer 5 is cleaved to obtain a semiconductor laser chip 3 (FIG. 2B, step S12 in FIG. 3).

Thereafter, a heat sink 4 is bonded to the crystal growth layer 32 side of the semiconductor laser chip 3 (FIG. 2C, FIG.
Step S13) In this state, the back surface of the substrate 31 is several μm
The thickness is reduced to a thickness of about several tens μm, for example, 5 μm (FIG. 2D, step S14 in FIG. 3). Examples of the method for thinning include a mechanical method by polishing, a chemical method by etching, and a method by sputtering. Then, an electrode 33 is formed on the back surface of the substrate 31 to obtain the semiconductor laser device shown in FIG.

According to the first embodiment, a semiconductor laser chip 3 having a crystal growth layer 32 and the like formed on a substrate 31 is cleaved to obtain a semiconductor laser chip 3. Since the heat sink 4 serves as a reinforcing material, the semiconductor laser chip 3 can be stably thinned without being damaged. Further, damage during wafer material handling is reduced, and the yield is improved.

Further, according to the first embodiment, in the thinning process as in the prior art, the labor for attaching the semiconductor laser chip 3 to a reinforcing material such as a glass plate can be omitted, and the process can be simplified and the member cost can be reduced. I can do it.

According to the first embodiment, the thickness of the substrate 31 can be easily set to several μm to several tens of μm, so that the thermal resistance of the substrate 31 is significantly reduced as compared with the conventional case of several hundred μm. Since the size can be reduced and the cooling efficiency from the substrate 31 side is extremely improved, it is suitable for manufacturing a high-output semiconductor laser.

Embodiment 2 Another method of manufacturing the semiconductor laser device shown in FIG. 1 will be described with reference to FIGS. 4 and 5 are a schematic diagram and a process diagram, respectively, showing another example of the manufacturing process of the semiconductor laser device shown in FIG.

First, a crystal growth layer 32 and a surface electrode 34 (omitted in FIG. 4, see FIG. 1) are formed on a semiconductor substrate 31 having a thickness of several hundred μm to obtain a semiconductor laser wafer 5 (FIG. 4).
(A), FIG. 5 step S21), a crystalline heat sink wafer 40 is bonded to the crystal growth layer 32 side of the semiconductor laser wafer 5 (FIG. 4 (b), FIG. 5 step S22).
In this state, the back surface of the semiconductor laser wafer 5 is thinned to a thickness of several μm to several tens μm, for example, 5 μm by mechanical polishing, etching, sputtering, or the like (FIG. 4C,
FIG. 5 step S23).

After an electrode 33 (omitted in FIG. 4, see FIG. 1) is formed on the back surface of the semiconductor laser wafer 5, a scribe line is formed between the semiconductor laser wafer 5 and the heat sink wafer 40 by a scriber, and an external force is applied thereto. The heat sink wafer 40 and the semiconductor laser wafer 5 are simultaneously cleaved (FIG. 4D, step S24 in FIG. 5) to obtain the semiconductor laser device shown in FIG.

According to the second embodiment, the semiconductor laser wafer 5 having the crystal growth layer 32 and the like formed on the substrate 31 is bonded to the heat sink wafer 40, and the semiconductor laser wafer 5 is thinned in this state. Since the wafer 40 serves as a reinforcing material, the semiconductor laser wafer 5 can be stably thinned without being damaged, and the heat sink wafer 40 and the semiconductor laser wafer 5 are cleaved together after the thinning. 3 can be obtained, and the yield is improved.

Further, according to the second embodiment, in the thinning process as in the related art, the labor for attaching the semiconductor laser wafer 5 to a reinforcing material such as a glass plate can be omitted, and the process can be simplified and the member cost can be reduced. .

According to the second embodiment, since the thickness of the substrate 31 can be easily set to several μm to several tens of μm, the thermal resistance of the substrate 31 is significantly reduced as compared with the conventional case of several hundred μm. Since the size can be reduced and the cooling efficiency from the substrate 31 side is extremely improved, it is suitable for manufacturing a high-output semiconductor laser.

Embodiment 3 FIG. Another method of manufacturing the semiconductor laser device shown in FIG. 1 will be described with reference to FIGS. 6 and 7 are a schematic diagram and a process chart, respectively, showing another example of the manufacturing process of the semiconductor laser device shown in FIG.

First, a crystal growth layer 32 and a surface electrode 34 (omitted in FIG. 6,
1) to obtain a semiconductor laser wafer 5 (FIG. 6).
(A), FIG. 7 step S31), a plurality of heat sinks 4 are arranged and joined to the crystal growth layer 32 side of the semiconductor laser wafer 5 (FIG. 6 (b), FIG. 7 step S32). At this time, the size of each heat sink 4 is set to be equal to or smaller than the size of the semiconductor laser chip 3 obtained by the subsequent cleavage, and alignment is performed so that each heat sink 4 can be joined to each semiconductor laser chip 3. Do.

In a state in which they are joined, the back surface of the semiconductor laser wafer 5 is thinned to a thickness of several μm to several tens μm, for example, 5 μm by mechanical polishing, etching, sputtering, or the like (FIG. 6C, FIG. 7 Step S33). Then, after an electrode 33 (omitted in FIG. 6, see FIG. 1) is formed on the back surface of the semiconductor laser wafer 5, the semiconductor laser wafer 5
A scribe line is inserted into the wafer by a scriber, and an external force is applied thereto to cleave the semiconductor laser wafer 5 (FIG. 6).
(D), FIG. 7 step S34), the semiconductor laser device shown in FIG. 1 is obtained.

According to the third embodiment, a plurality of heat sinks 4 are arranged and joined to a semiconductor laser wafer 5 having a crystal growth layer 32 and the like formed on a substrate 31, and the semiconductor laser wafer 5 is thinned in this state. , Heat sink 4
Can be used as a reinforcing material to stably reduce the thickness of the semiconductor laser wafer 5 without damaging the semiconductor laser wafer 5, and to cleave the semiconductor laser wafer 5 after the thinning. Is improved.

Further, according to the third embodiment, in the thinning process as in the related art, the labor for attaching the semiconductor laser wafer 5 to a reinforcing material such as a glass plate can be omitted, and the process can be simplified and the member cost can be reduced. .

According to the third embodiment, since the thickness of the substrate 31 can be easily set to several μm to several tens μm, the thermal resistance of the substrate 31 is significantly reduced as compared with the conventional case of several hundred μm. Since the size can be reduced and the cooling efficiency from the substrate 31 side is extremely improved, it is suitable for manufacturing a high-output semiconductor laser.

Embodiment 4 FIG. Another method of manufacturing the semiconductor laser device shown in FIG. 1 will be described with reference to FIGS. 8 and 9 are a schematic diagram and a process diagram, respectively, showing another example of the manufacturing process of the semiconductor laser device shown in FIG.

First, a crystal growth layer 32 and a surface electrode 34 (omitted in FIG. 8, see FIG. 1) are formed on a semiconductor substrate 31 having a thickness of several hundred μm to obtain a semiconductor laser wafer 5 (FIG. 8).
(A), FIG. 9 step S41), a heat sink wafer 42 in which a groove is cut is joined to the crystal growth layer 32 side of the semiconductor laser wafer 5 (FIG. 8 (b), FIG. 9 step S).
42).

The groove of the heat sink wafer 42 is provided at the same position as the cleavage site of the semiconductor laser wafer 5, and the groove is aligned with the cleavage site of the semiconductor laser wafer 5 at the time of bonding. Heat sink wafer 4
The thickness of the groove portion 2 is set in consideration of the ease of division at the time of cleavage later. For example, when the heat sink material is CuW, the thickness of the groove portion is appropriately from 10 μm to 50 μm. is there.

With the heat sink wafer 42 joined to the semiconductor laser wafer 5, the back surface of the semiconductor laser wafer 5 is several μm thick by mechanical polishing, etching or sputtering.
The thickness is reduced to a thickness of 数 10 μm, for example, 5 μm (FIG. 8C, step S43 in FIG. 9). Then, an electrode 33 (omitted in FIG. 8,
After forming the semiconductor laser wafer 5, a scribe line is formed in the semiconductor laser wafer 5 with a scriber, and an external force is applied to the semiconductor laser wafer 5 to cleave the semiconductor laser wafer 5 and the heat sink wafer 42 together (FIG. 8D, step S44 in FIG. 9). ,
The semiconductor laser device shown in FIG. 1 is obtained.

According to the fourth embodiment, the heat sink wafer 42 is bonded to the semiconductor laser wafer 5 having the crystal growth layer 32 and the like formed on the substrate 31, and the semiconductor laser wafer 5 is thinned in this state. Since the wafer 42 serves as a reinforcing material, the semiconductor laser wafer 5 can be stably thinned without being damaged, and since the semiconductor laser wafer 5 is cleaved after the thinning, the semiconductor laser chip 3 can be stably obtained. , And the yield is improved.

Further, according to the fourth embodiment, in the thinning process as in the related art, the labor for attaching the semiconductor laser wafer 5 to a reinforcing material such as a glass plate can be omitted, and the process can be simplified and the member cost can be reduced. .

According to the fourth embodiment, the thickness of the substrate 31 can be easily set to several μm to several tens μm, so that the thermal resistance of the substrate 31 is significantly reduced as compared with the conventional case of several hundred μm. Since the size can be reduced and the cooling efficiency from the substrate 31 side is extremely improved, it is suitable for manufacturing a high-output semiconductor laser.

Embodiment 5 FIG. FIG. 10 is a longitudinal sectional view showing another example of the semiconductor laser device according to the present invention. In this semiconductor laser device, the heat sink 6 is also joined to the substrate 31 side of the semiconductor laser chip 3 of the semiconductor laser device shown in FIG. Same as the device. Therefore, the same components are denoted by the same reference numerals as in FIG. 1 and description thereof is omitted.

A method of manufacturing the semiconductor laser device shown in FIG. 10 will be described with reference to FIGS.
11 and 12 are a schematic diagram and a process diagram showing an example of a manufacturing process of the semiconductor laser device shown in FIG. 10, respectively.

First, a crystal growth layer 32 and a surface electrode 34 (omitted in FIG. 11, on a semiconductor substrate 31 having a thickness of several hundred μm)
10 (see FIG. 10) to obtain a semiconductor laser wafer 5 (FIG. 11A, step S51 in FIG. 12), and a crystalline heat sink wafer 40 is bonded to the crystal growth layer 32 side of the semiconductor laser wafer 5 (FIG. b), FIG. 12, step S52). In this state, the back surface of the semiconductor laser wafer 5 is
The thickness is reduced to several μm to several tens μm, for example, 5 μm by mechanical polishing, etching, sputtering, or the like (FIG. 11C, step S53 in FIG. 12).

After an electrode 33 (omitted in FIG. 11, see FIG. 10) is formed on the back surface of the semiconductor laser wafer 5,
The crystalline heat sink wafer 60 is bonded to the substrate 31 side of the semiconductor laser wafer 5 (FIG. 11D, FIG. 12, step S54). Subsequently, scribe lines are formed in the heat sink wafers 40 and 60 by a scriber, and an external force is applied thereto to simultaneously cleave the heat sink wafers 40 and 60 and the semiconductor laser wafer 5 (FIG. 11E, step S55 in FIG. 12), and FIG. Is obtained.

According to the fifth embodiment, the semiconductor laser wafer 5 having the crystal growth layer 32 and the like formed on the substrate 31 is joined to the heat sink wafer 40, and the semiconductor laser wafer 5 is thinned in this state. The semiconductor laser wafer 5 can be stably thinned without damaging the semiconductor laser wafer 5, and the heat sink wafers 40, 60 and the semiconductor laser wafer 5 are cleaved together after the thinning. The laser chip 3 can be obtained, and the yield is improved.

Further, according to the fifth embodiment, in the thinning process as in the related art, the labor for attaching the semiconductor laser wafer 5 to a reinforcing material such as a glass plate can be omitted, and the process can be simplified and the member cost can be reduced. .

According to the fifth embodiment, the thickness of the substrate 31 can be easily set to several μm to several tens μm, so that the thermal resistance of the substrate 31 is significantly reduced as compared with the conventional case of several hundred μm. Since the heat sink 6 can be made smaller and the heat sink 6 is also joined to the substrate 31 side, the cooling efficiency from the substrate 31 side is improved as compared with the laser device shown in FIG. 1, which is suitable for manufacturing a higher output semiconductor laser. is there.

The heat sink 6 bonded to the substrate 31 may be a heat sink having a size equal to or smaller than the semiconductor laser chip size, as in the third embodiment, or a fourth embodiment. In the same manner as described above, it may be obtained from a heat sink wafer in which a groove is formed at the same position as the cleavage site of the semiconductor laser wafer.

Embodiment 6 FIG. Another manufacturing method of the semiconductor laser device shown in FIG. 10 will be described with reference to FIGS. 13 and 14 are a schematic diagram and a process chart, respectively, showing another example of the manufacturing process of the semiconductor laser device shown in FIG.

First, a crystal growth layer 32 and a surface electrode 34 (omitted in FIG. 13, see FIG. 10) are formed on a semiconductor substrate 31 having a thickness of several hundred μm to obtain a semiconductor laser wafer 5 (FIG. 13A). In FIG. 14, step S61), a plurality of heat sinks 4 are arranged and joined to the crystal growth layer 32 side of the semiconductor laser wafer 5 (FIG. 13B, FIG. 14, step S62). At this time, the size of each heat sink 4 is set equal to or smaller than the size of the semiconductor laser chip 3 obtained by the subsequent cleavage.
Are positioned so that the heat sinks 4 can be joined together.

In the state where these are joined, the back surface of the semiconductor laser wafer 5 is thinned to a thickness of several μm to several tens μm, for example, 5 μm by mechanical polishing, etching, sputtering, or the like (FIG. 13C, FIG. 14 step S63).
Then, an electrode 33 (see FIG.
3 (not shown, see FIG. 10), a plurality of heat sinks 6 are arranged and joined to the substrate 31 side of the semiconductor laser wafer 5 (FIG. 13D, step S64 in FIG. 14).

At this time, the size of each heat sink 6 is set equal to or smaller than the size of the semiconductor laser chip 3 obtained by the subsequent cleavage.
Are aligned so that the heat sinks 6 can be joined together. Subsequently, an external force is applied to cleave the semiconductor laser wafer 5 (FIG. 13E, step S65 in FIG. 14), and FIG.
Is obtained.

According to the sixth embodiment, a plurality of heat sinks 4 are arranged and joined to a semiconductor laser wafer 5 having a crystal growth layer 32 and the like formed on a substrate 31, and the semiconductor laser wafer 5 is thinned in this state. , Heat sink 4
Can be used as a reinforcing material to stably reduce the thickness of the semiconductor laser wafer 5 without damaging it. In addition, after the thinning, the heat sink 4 is arranged and joined to the semiconductor laser wafer 5 to be cleaved. And yield is improved.

Further, according to the sixth embodiment, in the thinning process as in the related art, the labor for attaching the semiconductor laser wafer 5 to a reinforcing material such as a glass plate can be omitted, and the process can be simplified and the member cost can be reduced. .

According to the sixth embodiment, since the thickness of the substrate 31 can be easily set to several μm to several tens μm, the thermal resistance of the substrate 31 is significantly reduced as compared with the conventional case of several hundred μm. Since the heat sink 6 can be made smaller and the heat sink 6 is also joined to the substrate 31 side, the cooling efficiency from the substrate 31 side is improved as compared with the laser device shown in FIG. 1, which is suitable for manufacturing a higher output semiconductor laser. is there.

The heat sink 6 joined to the substrate 31 may be obtained from a crystalline heat sink wafer as in the fifth embodiment, or may be formed from a crystalline heat sink wafer as in the fourth embodiment. It may be obtained from a heat sink wafer in which a groove is formed at the same position as a cleavage site of a semiconductor laser wafer.

Embodiment 7 FIG. Another manufacturing method of the semiconductor laser device shown in FIG. 10 will be described with reference to FIGS. 15 and 16 are a schematic diagram and a process chart showing another example of the manufacturing process of the semiconductor laser device shown in FIG.

First, a crystal growth layer 32 and a surface electrode 34 (omitted in FIG. 15, see FIG. 10) are formed on a semiconductor substrate 31 having a thickness of several hundred μm to obtain a semiconductor laser wafer 5 (FIG. 15A). Then, a heat sink wafer 42 in which a groove is formed is bonded to the crystal growth layer 32 side of the semiconductor laser wafer 5 (FIG. 15B, FIG. 16 step S72).

The groove of the heat sink wafer 42 is provided at the same position as the planned cleavage of the semiconductor laser wafer 5, and the groove is aligned with the planned cleavage of the semiconductor laser wafer 5 at the time of bonding. Heat sink wafer 4
The thickness of the groove portion 2 is set in consideration of the ease of division at the time of cleavage later. For example, when the heat sink material is CuW, the thickness of the groove portion is appropriately from 10 μm to 50 μm. is there.

With the heat sink wafer 42 joined to the semiconductor laser wafer 5, the back surface of the semiconductor laser wafer 5 is several μm thick by mechanical polishing, etching or sputtering.
The thickness is reduced to a thickness of up to several tens μm, for example, 5 μm (FIG. 15C, step S73 in FIG. 16). Then, after an electrode 33 (omitted in FIG. 15, see FIG. 10) is formed on the back surface of the semiconductor laser wafer 5, the semiconductor laser wafer 5
Heat sink wafer 6 having grooves formed on the substrate 31 side
1 (FIG. 15D, step S7 in FIG. 16).
4).

The position of the groove of the heat sink wafer 61 and the thickness of the groove portion are the same as those of the groove of the heat sink wafer 42 described above, and therefore, the description is omitted. At the time of bonding, the position of the groove of the heat sink wafer 61 and the position to be cleaved of the semiconductor laser wafer 5 are aligned. Subsequently, an external force is applied to cleave the semiconductor laser wafer 5 and the heat sink wafers 42, 61 together (FIG. 15 (e), step S75 in FIG. 16) to obtain the semiconductor laser device shown in FIG.

According to the seventh embodiment, the heat sink wafer 42 is bonded to the semiconductor laser wafer 5 having the crystal growth layer 32 and the like formed on the substrate 31, and the semiconductor laser wafer 5 is thinned in this state. Since the wafer 42 serves as a reinforcing material, the semiconductor laser wafer 5 can be stably thinned without being damaged, and after the thinning, the heat sink wafer 61 is joined to the semiconductor laser wafer 5 and cleaved. 3 can be obtained, and the yield is improved.

Further, according to the seventh embodiment, in the thinning process as in the related art, the labor for attaching the semiconductor laser wafer 5 to a reinforcing material such as a glass plate can be omitted, and the process can be simplified and the member cost can be reduced. .

Further, according to the seventh embodiment, the thickness of substrate 31 can be easily set to several μm to several tens μm, so that the thermal resistance of substrate 31 is significantly reduced as compared with the conventional case of several hundred μm. Since the heat sink 6 can be made smaller and the heat sink 6 is also joined to the substrate 31 side, the cooling efficiency from the substrate 31 side is improved as compared with the laser device shown in FIG. 1, which is suitable for manufacturing a higher output semiconductor laser. is there.

The heat sink 6 to be bonded to the substrate 31 may be obtained from a crystalline heat sink wafer as in the fifth embodiment, or may be formed from a crystalline heat sink wafer as in the sixth embodiment. A heat sink having a size equal to or smaller than the semiconductor laser chip size may be used.

In the above, the present invention can be variously modified as long as the semiconductor wafer or chip is joined to the heat sink and then the heat sink is used as a reinforcing material to reduce the thickness. The semiconductor substrate 31 is G
Not limited to aAs, other compound semiconductors such as InP may be used. Further, the present invention is not limited to a laser diode, but can be applied to a light emitting diode and a photodiode.

[0074]

As described above, according to the present invention, according to the present invention, a heat sink is joined to the crystal growth layer side of a semiconductor laser chip, and in this state, the substrate of the semiconductor laser chip is reduced by several μm.
m to several tens of μm, preferably 5 μm, so that the heat sink serves as a reinforcing material to stably reduce the thickness of the semiconductor laser chip without damaging it. A high-output semiconductor laser with excellent cooling efficiency can be obtained.

According to the next invention, a heat sink wafer is joined to the crystal growth layer side of the semiconductor laser wafer, and in this state, the substrate of the semiconductor laser wafer is thinned to a thickness of several μm to several tens μm, preferably 5 μm. As a result, the heat sink wafer serves as a reinforcing material so that the semiconductor laser wafer can be stably thinned without being damaged, and after the thinning, the heat sink wafer and the semiconductor laser wafer are cleaved together, so that the semiconductor laser wafer is stably formed. Since a chip can be obtained, a high-output semiconductor laser with excellent cooling efficiency from the substrate side can be obtained with high yield.

According to the next invention, a heat sink is joined to the crystal growth layer side of the semiconductor laser wafer, and in this state, the substrate of the semiconductor laser wafer is thinned to a thickness of several μm to several tens μm, preferably 5 μm. Therefore, the semiconductor laser wafer can be stably thinned without being damaged by the heat sink serving as a reinforcing material, and the semiconductor laser wafer can be stably obtained by cleaving the semiconductor laser wafer after the thinning. In addition, a high-output semiconductor laser with excellent cooling efficiency from the substrate side can be obtained with high yield.

According to the next invention, a heat sink wafer is bonded to the crystal growth layer side of the semiconductor laser wafer, and in this state, the substrate of the semiconductor laser wafer is thinned to a thickness of several μm to several tens μm, preferably 5 μm. As a result, the heat sink wafer serves as a reinforcing material so that the semiconductor laser wafer can be stably thinned without being damaged, and the heat sink wafer and the semiconductor laser wafer are cleaved after the thinning. Therefore, a high-output semiconductor laser with excellent cooling efficiency from the substrate side can be obtained with high yield.

According to the next invention, a heat sink wafer is joined to the crystal growth layer side of the semiconductor laser wafer, and in this state, the substrate of the semiconductor laser wafer is thinned to a thickness of several μm to several tens μm, preferably 5 μm. As a result, the heat sink wafer serves as a reinforcing material to stably reduce the thickness of the semiconductor laser wafer without damaging the semiconductor laser wafer. After the thinning, the heat sink wafer or the heat sink is joined to the substrate side of the semiconductor laser wafer and then cleaved. Therefore, a semiconductor laser chip having a heat sink also joined to the substrate side can be obtained stably, and a high-output semiconductor laser with even more excellent cooling efficiency from the substrate side can be obtained with good yield.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing an example of a semiconductor laser device according to the present invention.

FIG. 2 is a schematic view showing an example of a manufacturing process of the semiconductor laser device.

FIG. 3 is a process chart showing the manufacturing process.

FIG. 4 is a schematic view showing another example of the manufacturing process of the semiconductor laser device.

FIG. 5 is a process chart showing the manufacturing process.

FIG. 6 is a schematic view showing another example of the manufacturing process of the semiconductor laser device.

FIG. 7 is a process chart showing the manufacturing process.

FIG. 8 is a schematic view showing another example of the manufacturing process of the semiconductor laser device.

FIG. 9 is a process chart showing the manufacturing process.

FIG. 10 is a longitudinal sectional view showing another example of the semiconductor laser device according to the present invention.

FIG. 11 is a schematic view showing an example of a manufacturing process of the semiconductor laser device.

FIG. 12 is a process chart showing the manufacturing process.

FIG. 13 is a schematic view showing another example of the manufacturing process of the semiconductor laser device.

FIG. 14 is a process chart showing the manufacturing process.

FIG. 15 is a schematic view showing another example of the manufacturing process of the semiconductor laser device.

FIG. 16 is a process chart showing the manufacturing process.

FIG. 17 is a longitudinal sectional view showing a conventional high-power semiconductor laser device.

FIG. 18 is a longitudinal sectional view showing a conventional high-power semiconductor laser device.

[Explanation of symbols]

3 semiconductor laser chip, 31 semiconductor substrate, 32 crystal growth layer, 34 electrodes, 4, 6 heat sink, 40,
42, 60, 61 heat sink wafer, 5 semiconductor laser wafer.

Claims (5)

[Claims] A step of forming a crystal growth layer on one main surface of a semiconductor substrate and an electrode thereon to obtain a semiconductor laser wafer; a step of cleaving the semiconductor laser wafer to obtain a semiconductor laser chip; Bonding a heat sink to the crystal growth layer side of the chip; and bonding the heat sink to the substrate side surface of the semiconductor laser chip with the substrate having a thickness of several μm to several tens μm.
A method of reducing the thickness of the semiconductor laser device to a thickness of preferably 5 μm. 2. A step of forming a crystal growth layer on one principal surface of a semiconductor substrate and an electrode thereon to obtain a semiconductor laser wafer, and a step of bonding a crystalline heat sink wafer to the crystal growth layer side of the semiconductor laser wafer. A step of thinning the substrate-side surface of the semiconductor laser wafer with the heat sink wafer bonded thereto until the thickness of the substrate becomes several μm to several tens μm, preferably 5 μm; Cleaving the obtained semiconductor laser wafer together with the heat sink wafer. 3. A step of forming a crystal growth layer on one main surface of a semiconductor substrate and an electrode thereon to obtain a semiconductor laser wafer, and forming a plurality of heat sinks on the crystal growth layer side of the semiconductor laser wafer by cleavage. Aligning and joining them so that they can be respectively joined to a plurality of chips that can be obtained; and joining the heat sink to the substrate side surface of the semiconductor laser wafer with the heat sink joined, the thickness of the substrate being several μm to several μm. 10 μm,
A method for manufacturing a semiconductor laser device, comprising: a step of thinning the semiconductor laser wafer to a thickness of preferably 5 μm; and a step of cleaving the thinned semiconductor laser wafer. 4. A step of forming a crystal growth layer on one main surface of a semiconductor substrate and an electrode thereon to obtain a semiconductor laser wafer, and forming a heat sink wafer having a groove on the crystal growth layer side of the semiconductor laser wafer. A step of aligning and joining the grooves so that they match the planned cleavage positions of the semiconductor laser wafer; and bonding the heat sink wafer to the substrate side surface of the semiconductor laser wafer with the substrate having a thickness of several μm to A method for manufacturing a semiconductor laser device, comprising: a step of thinning a semiconductor laser wafer to a thickness of several tens of μm, preferably 5 μm; and a step of cleaving the thinned semiconductor laser wafer together with a heat sink wafer. 5. The method according to claim 2, further comprising the step of joining a heat sink wafer or a plurality of heat sinks to the substrate side of the thinned semiconductor laser wafer.
5. The method for manufacturing a semiconductor laser device according to any one of items 4.