JP2000004064A - Semiconductor laser device and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a semiconductor laser device by which manufacture cost and maintenance cost can be reduced and which can prevent the extrusion and the oxidation of a solder film and to provide the manufacturing method. SOLUTION: A solder film 14 is formed in the prescribed position of a semiconductor laser element 16 by using highly precise thin film forming technology such as vapor deposition and photolithography. The semiconductor laser element 16 is positioned on the upper face of a sub-mount 12 heated to a prescribed temperature under the condition where the solder film 14 is brought into contact with it. Then, the solder film 14 is melted by the heat of the sub-mount 12, and the semiconductor laser element 16 is directly jointed with the sub-mount 12. Thus, the oxidation of the solder film 14 by preliminary heating can be prevented. Since the solder film 14 can precisely be formed in the prescribed position of the semiconductor laser element 16, the melted solder film 14 is prevented from extruding to the side of the semiconductor laser element 16.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor laser device and a method of manufacturing the same, and more particularly, for example, to a CD, DVD,
The present invention relates to a semiconductor laser device used for an LBP pointer, a bar code reader, or the like, in which a semiconductor laser element is bonded on a submount with a solder film, and a method for manufacturing such a semiconductor laser device.

[0002]

2. Description of the Related Art FIG. 4 shows a conventional method for manufacturing a semiconductor laser device. In this prior art, first, as shown in FIG. 4A, a submount 2 having a solder film 1 formed on an upper surface is prepared, and the submount 2 and the solder film 1 are immersed in a nitrogen (N ₂ ) atmosphere. Preheating by means of a heater 3a. continue,
As shown in FIG. 4 (B), the semiconductor laser element 4 is positioned at the portion of the submount 2 where the solder film 1 is formed, and the submount 2 and the solder film 1 are fully heated by a heater 3b. 1 is melted. After that, the submount 2 is cooled to solidify the solder film 1.

In the prior art, the preheating is performed to shorten the time required for the main heating, and the preheating is performed in a nitrogen (N ₂ ) atmosphere because the solder film 1 is preheated. This is for preventing oxidation (deterioration).

[0004]

In the prior art, a special device was required to create a nitrogen atmosphere, and thus there was a problem that the manufacturing cost and the maintenance cost were increased. Further, since it is difficult to accurately position the semiconductor laser element 4 right above the solder film 1 formed in a micro-unit size, there is a possibility that a positional shift may occur between them. When such a displacement occurs, as shown in FIG. 5, the molten solder film 1 protrudes to the side surface of the semiconductor laser element 4 to block the laser emission port 5 and to prevent the current path (particularly double current). (Hetero region).

[0005] Therefore, a main object of the present invention is to provide a semiconductor laser device and a method of manufacturing the same, which can reduce the manufacturing cost and the maintenance cost, and can prevent the solder film from sticking out and oxidizing.

[0006]

According to a first aspect of the present invention, in a semiconductor laser device in which a semiconductor laser element is bonded on a submount with a solder film, a solder film is formed on the semiconductor laser element in advance. A semiconductor laser device characterized by doing so. According to a second aspect of the present invention, (a) a solder film is formed on the surface of a semiconductor laser device, (b) a submount heated to a predetermined temperature higher than a melting temperature of the solder film is prepared, and (c) an upper surface of the submount is provided. This is a method for manufacturing a semiconductor laser device in which a semiconductor laser element is positioned on an upper surface in a state where a solder film is in contact with the semiconductor laser device.

[0007]

When the semiconductor laser device is positioned on the upper surface of the submount and the upper surface of the submount is brought into contact with the solder film formed on the surface of the semiconductor laser device, the heat of the submount melts the solder film and the semiconductor film is melted. The laser element and the submount are immediately joined. Therefore, it is not necessary to preheat the solder film. Further, since the solder film is formed on the semiconductor laser element side in advance, even if the submount is preliminarily heated, the heat is not transmitted to the solder film. Further, when a solder film is formed at a predetermined position on the surface of the semiconductor laser element, a high-precision thin film forming technique such as vapor deposition or photolithography can be used.

[0008]

According to the present invention, oxidation of the solder film due to preheating can be prevented. Therefore, there is no need to provide a device for creating a nitrogen atmosphere as in the related art, so that manufacturing costs and maintenance costs can be reduced. In addition, since the solder film can be accurately formed at a predetermined position of the semiconductor laser element, it is possible to prevent the solder film from protruding to the side surface of the semiconductor laser element, thereby preventing the laser emission port from being clogged by the protruding solder film and the short circuit of the current path. it can.

The above objects, other objects, features and advantages of the present invention will become more apparent from the following detailed description of embodiments with reference to the drawings.

[0010]

1 shows a semiconductor laser device 1 according to this embodiment shown in FIG.
0 is built in a CD, DVD, bar code reader, or the like, and includes silicon (Si), silicon carbide (S
i. C., a rectangular parallelepiped submount 12 made of aluminum nitride (AlN), diamond, or the like. The solder film 14 made of a gold (Au) -tin (Sn) alloy, a lead (Pb) -tin (Sn) alloy, an indium (In) -tin (Sn) alloy, or the like is provided on the upper surface of the submount 12. Thus, the semiconductor laser element 16 is joined.

The semiconductor laser device 16 includes a substrate 18,
A first electrode 20a is formed on one main surface of the substrate 18, and a first clad layer 22, an active layer 24, a second clad layer 26, a contact layer 28, and a second electrode 20b are formed on the other main surface. Then, in order to efficiently transfer the heat generated in the active layer 24 to the submount 12, the electrode on the short side of the double hetero section including the active layer 24, that is, the second electrode
The electrode 20b is joined to the submount 12.

A method for manufacturing the semiconductor laser device 10 will be described below with reference to FIG. First, as shown in FIG. 2A, a plurality of semiconductor laser elements 16a are formed on a GaAs wafer 30 constituting the substrate 18. That is, the first clad layer 22, the active layer 24, the second clad layer 26, and the contact layer 28 shown in FIG. The first electrode 20a and the second electrode
The electrode 20b is formed by sputtering.

The solder film 1 is formed on the entire surface of the second electrode 20b.
After vapor deposition of the solder film 14, as shown in FIG.
Is removed by photolithography. That is, the solder film 14 is masked with a patterned photoresist, and unnecessary portions are removed by etching, so that the solder film 1 is placed at a predetermined position of the semiconductor laser element 16a.
4 is formed. Here, the thickness and the formation position of the solder film 14 need to be set so as to prevent the melted solder film 14 from protruding to the side surface of the semiconductor laser element 16. Therefore, in this embodiment, the thickness of the solder film 14 is set to 3
μm or less, and the formation position is set to be 10 μm or more inward from the periphery of the semiconductor laser element 16.

Subsequently, as shown in FIG.
Semiconductor laser device 16a fabricated on wafer 30
Of the semiconductor laser device 1 by cleaving
Get 6. On the other hand, as shown in FIG. 3D, by heating the submount 12 formed in a rectangular parallelepiped shape by the heater 32, the temperature is set to a predetermined temperature higher than the melting temperature of the solder film 14. For example, when the solder film 14 is made of gold (A
u) -tin (Sn) alloy (Au / Sn = 70 wt./% 3)
0 wt./%), the melting temperature is 300
° C, the temperature of the submount 12 is
Set to about 350 ° C.

Then, as shown in FIG. 3E, the semiconductor laser element 16 is positioned by a mounting device (not shown) in a state where the solder film 14 is in contact with the upper surface of the submount 12. When the time required for the solder film 14 to completely melt has elapsed, the heating by the heater 32 is stopped, and the submount 12 is cooled. According to this embodiment, since the solder film 14 can be instantaneously melted by the submount 12 heated to a temperature higher than the melting temperature of the solder film 14, it is not necessary to preheat the solder film 14. Therefore, the oxidation of the solder film 14 due to the preheating can be reliably prevented.

When the solder film 14 is formed at a predetermined position on the semiconductor laser element 16a, the solder film 14 can be formed accurately by a known thin film forming technique such as vapor deposition or photolithography. Therefore, by appropriately setting the thickness and the formation position of the solder film 14, the molten solder film 14 can be prevented from protruding to the side surface of the semiconductor laser element 16, and
Blockage of the laser emission port and short circuit of the current path can be prevented.

In the above embodiment, the submount 1
2 is not preheated, but the submount 12 may be preheated before the step of FIG. Also in this case, since the solder film 14 is formed on the semiconductor laser element 16 side in advance, the heat of the submount 12 is not transmitted to the solder film 14, and the solder film 14 is not oxidized by the preheating.

[Brief description of the drawings]

FIG. 1 is an illustrative view showing one embodiment of the present invention;

FIG. 2 is an illustrative view showing a manufacturing method of the embodiment in FIG. 1;

FIG. 3 is an illustrative view showing a manufacturing method of the embodiment in FIG. 1;

FIG. 4 is an illustrative view showing a conventional method for manufacturing a semiconductor device;

FIG. 5 is an illustrative view showing a state in which a solder film protrudes from a side surface of a semiconductor laser device in a conventional technique.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Semiconductor laser device 12 ... Submount 14 ... Solder material 16 ... Semiconductor laser element

Claims (5)

[Claims] 1. A semiconductor laser device in which a semiconductor laser element is bonded on a submount with a solder film, wherein the solder film is formed on the semiconductor laser element in advance. , Semiconductor laser devices. 2. A semiconductor laser device comprising: a solder film formed on a surface thereof; (b) a submount heated to a predetermined temperature higher than a melting temperature of the solder film; A method for manufacturing a semiconductor laser device, wherein the semiconductor laser element is positioned on the upper surface while the solder film is in contact with the upper surface. 3. The method of manufacturing a semiconductor laser device according to claim 2, wherein said solder film has a thickness of 3 μm or less. 4. The semiconductor laser device according to claim 2, wherein said solder film is formed at least 10 μm inward from a peripheral edge of said semiconductor laser device.
4. A method for manufacturing a semiconductor laser device according to item 3. 5. The method according to claim 2, wherein the step (a) includes a step of forming a solder film on the surface of the semiconductor laser device, and a step of masking the solder film with a resist to remove unnecessary portions by etching. 5. The method for manufacturing a semiconductor laser device according to any one of items 4 to 4.