JPH10200203A - Semiconductor laser element and manufacturing method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the size by incorporating a Peltier effect element in a semiconductor laser element to directly cool heating parts. SOLUTION: A semiconductor laser element 120 comprises a p-clad layer 102, a guide layer 103, an active layer 104, a guide layer 105, an n-clad layer 106, a contact layer 107, and an emission driving electrode 108 on a p-type substrate 101. The n-clad layer 106 has ridges at the center and both ends on which a common electrode 109a and electrodes 109b, 109c to be driving anodes of a Peltier effect element are provided. A voltage V1 is applied to the electrode 108 and the common electrode 109a to drive the semiconductor laser element 120. A voltage V2 is applied to the common electrode 109a and electrodes 109b, 109c to flow a current I2 from the electrodes 109b, 109c to the common electrode 109a, resulting in a cooling action at the region of the common electrode 109a and heating action at the regions of the electrodes 109b, 109c due to the Peltier effect, thereby efficiently cooling a light emission part.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a semiconductor laser device and a method for manufacturing the same.

[0002]

2. Description of the Related Art Semiconductor laser devices are often used for optical communication and optical recording / reproduction, and in particular, have high output and excellent stability in response to recent demands for large capacity and high speed communication. Laser elements are required. In order to stably operate a high-output semiconductor laser device, it is necessary to cool and radiate heat generated in a light emitting portion of the semiconductor laser device. In general, device temperature control using a Peltier effect device is used.

FIG. 5 is a diagram showing an example of the configuration of a conventional cooling device for a semiconductor laser device using a Peltier effect device. The semiconductor laser element 501 is provided with the heat radiation member 5.
The semiconductor laser device 501 is mounted on the semiconductor device 02 so as to maintain good thermal conductivity, and generally transmits heat generated by the semiconductor laser element 501 to a heat-radiating member 502 having good thermal conductivity such as metal such as copper, silicon, and diamond. The heat radiation member 502 is mounted on the Peltier effect element 503 so as to maintain good thermal conductivity, and the Peltier effect element 503 is mounted on another heat radiation member 504 so as to maintain good heat conductivity.

As is well known, the Peltier effect element 503 has a plate-like configuration in which semiconductors of different conductivity types are electrically connected in series and sandwiched by a plate material such as ceramics.
A heat pump element having one of a plate surface as a heat absorber and the other as a heat generator depending on the direction in which the current flows. When a current is supplied from a drive circuit (not shown), heat is generated or absorbed in addition to Joule heat.

In FIG. 5, a Peltier effect element 503 is shown.
It is possible to conduct electricity so that the upper part is cooled and the lower part generates heat or vice versa, and by controlling this current,
The element and the heat radiating member 502 are controlled at a constant temperature. Further, the heat radiating member 504 is cooled by a cooling fan (not shown) or the like in order to finally release the generated heat to the outside.

In the semiconductor laser device 501 having the cooling means having the above-described structure, heat generated by the light emission drive current is conducted from the semiconductor laser device 501 to the heat radiating member 502, and the heat radiating member 502 is cooled by the Peltier effect element 503. The heat generated by the Peltier effect element 503 is dissipated into the atmosphere by the heat dissipation member 504.

Next, the structure and operation of a general semiconductor laser device will be described with reference to FIG. On an InP substrate 601, a p-cladding layer 602, a guide layer 603, an active layer 604 serving as a light emitting portion, a guide layer 605, and an n-cladding layer 60 are formed.
6, a contact layer 607 is grown and stacked in a predetermined order by an epitaxial growth method, a liquid phase growth method, a metal organic chemical vapor deposition method, a molecular beam growth method, or the like. An electrode 608 is provided below the InP substrate 601 and an electrode 60 is provided above the contact layer 607.
When a predetermined current is supplied from an external drive circuit (not shown) to a diode serving as a pn junction with the electrode 609 serving as an anode and the electrode 608 serving as a cathode, a current flows in the direction of the arrow shown in FIG. The laser light is radiated from a portion below the electrode 608 in a direction perpendicular to the plane of the drawing, and generates heat when energized.

[0008]

However, in the cooling method for a semiconductor laser device constructed as described above, the heat generated by the semiconductor laser device is transferred to the first heat radiating member by the first heat radiating member. Cooling, cooling of the Peltier effect element, heat conduction to the second heat radiating member, and cooling of the second heat radiating member require a process, and the cooling efficiency of the semiconductor laser element and the time response of temperature control are not good. was there.
In addition, there are problems that the cooling member has a complicated structure, and the semiconductor laser device including the cooling device cannot be downsized, and the cost increases.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and it is possible to directly cool a heat generating portion by incorporating a Peltier effect element in a semiconductor element and integrating the Peltier effect element with the semiconductor laser element. It is an object of the present invention to provide a semiconductor laser device which can be miniaturized, has high cooling efficiency, and a method for manufacturing the same.

[0010]

In order to solve the above problems, a semiconductor laser device according to a first aspect of the present invention is characterized in that a Peltier effect device is incorporated in a semiconductor laser device. A semiconductor laser device according to a second aspect of the present invention is the semiconductor laser device according to the first aspect, wherein a substrate and a p-type layer made of a p-type semiconductor material, an active layer, and an n-type semiconductor material are provided. And an electrode, wherein the Peltier effect element is formed on the n-type layer.

A semiconductor laser device according to a third aspect of the present invention is the semiconductor laser device according to the second aspect, wherein the electrode includes an electrode for flowing a current for driving the semiconductor laser device, and a Peltier effect. And an electrode for flowing a current for driving the element.

A semiconductor laser device according to a fourth aspect of the present invention is the semiconductor laser device according to the second or third aspect, wherein the n-type layer comprises an n-type cladding layer and an n-type contact layer. It is characterized by.

A semiconductor laser device according to a fifth aspect of the present invention is the semiconductor laser device according to the fourth aspect, wherein the periphery of the electrode for flowing a current for driving the semiconductor laser device of the n-type cladding layer is provided. Have an endothermic effect, and the periphery of the electrode for passing a current for driving the Peltier effect element has a heat dissipating effect.

According to a method of manufacturing a semiconductor laser device according to a sixth aspect of the present invention, in the method of manufacturing a semiconductor laser device, a substrate and a p-type layer made of a p-type semiconductor material are provided.
A step of laminating an active layer and an n-type layer made of an n-type semiconductor material, and a step of forming a ridge on the n-type layer.
Forming an electrode for flowing a current for driving a semiconductor laser element and an electrode for flowing a current for driving a Peltier effect element on the n-type layer after the ridge is formed.

[0015]

According to the present invention, by integrating the Peltier effect element and the semiconductor laser element as described above, the heat generating portion can be directly cooled, the semiconductor laser element can be reduced in size and has a high cooling efficiency, and a method of manufacturing the same. Can be provided.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In a semiconductor laser device according to the present invention,
The Peltier effect element is arranged close to the light emitting part of the semiconductor laser element using a part of the laser element constituent material, and the heat generated by the light emission of the semiconductor laser element is directly cooled by the Peltier effect element, and the heat generated by the Peltier effect element is generated. Is effectively radiated to the outside of the semiconductor laser device by an external device, thereby effectively cooling the semiconductor laser device.

FIG. 1 shows an embodiment of such a configuration. In FIG. 1, a semiconductor laser device 120 according to the present invention includes a p-type cladding layer 10 on a p-type substrate 101.
2, guide layer 103, active layer 104, guide layer 105,
An n-cladding layer 106 and a contact layer 107 are respectively laminated by crystal growth, and an electrode 108 serving as a light emission driving anode of the semiconductor laser device is provided on the p-type substrate 101 side.
A ridge is formed at each of a central portion and both end portions corresponding to the light emitting portion of the n-cladding layer 106, and a common electrode 109a serving as a light emission driving cathode and a Peltier effect device cathode, and an electrode serving as a Peltier effect device driving anode are formed on each ridge. 10
9b and 109c are provided.

The semiconductor laser device 120 having such a configuration is described.
Electrode 109a is connected to the ground potential, and a voltage V1 is applied to the electrode 108 so that a light emission drive current I1 flows, and the p-cladding layer 102 and the n-cladding layer 10
Electrode 109 through a pn junction diode composed of
A light emission drive current flows through a.

On the other hand, a voltage V2 is applied to the electrodes 109b and 109c between the electrodes 109b and 109c to drive the Peltier effect element. Then, the current is applied to the electrode 109.
b, 109c flows toward the common electrode 109a as I2. The semiconductor layer of the n-cladding layer 106 has an electrode 109 on the side into which the current I2 flows due to the Peltier effect.
b, 109c (near the n-cladding layer in contact with the electrodes 109b, 109c) generates heat, and I2
The cooling action occurs in the peripheral portion of the electrode 109a from which the semiconductor flows out (near the n-clad layer in contact with the electrode 109a), that is, above the light emitting portion of the semiconductor laser device.

Therefore, the heat generated by the Peltier effect is conducted to the outside from the n-cladding layer in contact with the electrodes 109b and 109c and radiated, thereby cooling the light emitting portion of the semiconductor laser device extremely efficiently. Becomes possible.

At this time, the voltage V2 of the electrodes 109b and 109c exceeds the breakdown voltage Ve of the np junction diode composed of the n-cladding layer 106 and the p-cladding layer 102 (about 10 V in a normal semiconductor laser device). Then, a large reverse current flows from the electrodes 109b and 109c to the electrode 108, and the element is likely to be destroyed. Therefore, V2 must not exceed this breakdown voltage.

Further, the Peltier drive voltage must always be higher than the laser drive voltage so that the laser drive current does not flow into the Peltier drive electrode. Moreover, it must be lower than the breakdown voltage Ve. That is, V2 is replaced by V1
Set within the range of <V2 <Ve.

FIG. 2 shows an example in which the above-described semiconductor laser device is mounted on a chip carrier 201 by soldering. The semiconductor laser device 210 according to the present invention is mounted on the chip carrier 201, and the semiconductor laser device 210
Are soldered to the chip carrier 201 via the insulator 203 and the metal conductor 204 by soldering. Therefore, the upper part of the light emitting unit located at the center of the semiconductor laser element 210 is directly cooled by the power supply from the external drive circuit (not shown) to the Peltier effect element,
Heat generated on both sides of the semiconductor laser element 210 as a heat generating portion of the Peltier effect element is conducted to the chip carrier 201 through the solder 202 and is radiated from the chip carrier 201 to the atmosphere. The example of FIG. 2 is an example, and there are various methods of heat radiation, such as forced air cooling by a fan and liquid cooling, and are not limited by the present embodiment.

Next, a method of manufacturing the semiconductor laser device having the above-described structure will be described in detail with reference to FIGS. FIG. 3 and FIG. 4 are views showing the manufacturing process of the semiconductor laser device according to the present invention. FIG. 3 (a)
4 (e) and the materials of the respective stacked layers of FIGS. 4 (a) to 4 (c). In a conventional semiconductor laser device, generally, an n-InP substrate is used as a substrate 301, and an electrode connected to this substrate is used as a cathode at a ground potential, and the other electrode is often used as an anode. In order to integrate with the Peltier effect element, p-type
An InP substrate is used.

On a p-InP substrate, InGaAs is formed.
A P guide layer 302, an InGaAsP active layer 303,
Guide layer 304 of InGaAsP, cladding layer 305 of n-InP, layer 306 of n-InGaAsP, n-In
GaAs contact layers 307 are respectively stacked.

FIG. 3B shows a state in which each layer made of these materials is formed by crystal growth. FIG.
As shown in FIG. 3C, the ridges 312a, 312b, 312c are formed by etching using a mask 308 as shown in FIG.

Next, as shown in FIG.
8 are removed, each ridge 312a, 312b, 312
An insulator 309 is buried so as to fill the space between c and the upper part is made a smooth surface. Thereafter, the insulator 309 is further etched to expose the surface of the n-InGaAs contact layer 307 as shown in FIG.

Next, as shown in FIG.
0 and 311 are formed on the upper and lower ends by vapor deposition or the like, respectively, and as shown in FIG. 4C, the electrode 311 is separated into three electrodes 311a, 311b and 311c by patterning to complete the semiconductor laser device of the present invention. I do. Here electrode 3
11a is for laser driving, and 311b and c are for Peltier driving.

As described above, in the semiconductor laser device according to the present invention, the Peltier effect device is integrated with the semiconductor laser device, and the cooling portion of the Peltier effect device is arranged in the vicinity of the light-emitting portion which is the most heat-generating portion of the semiconductor laser device. By doing so, the cooling efficiency is significantly improved. In addition, the conventional lamination method using crystal growth can be used as it is in the manufacturing method. In the above description, I
Although the description has been given of the nP-based semiconductor laser device, the present invention is not limited to the InP-based semiconductor laser device, and can be applied to a semiconductor laser device using another semiconductor material because it has a Peltier effect if it is a semiconductor material.

[0030]

As described above, according to the present invention, the heat generating portion of the semiconductor laser element can be directly cooled by the Peltier effect element, and the Peltier effect element and the semiconductor laser element which can be reduced in size and have high cooling efficiency can be provided. It is possible to provide an integrated semiconductor laser device.

[Brief description of the drawings]

FIG. 1 is a diagram showing a structure of a semiconductor laser device according to the present invention.

FIG. 2 is a diagram showing an example of a cooling method using a semiconductor laser device according to the present invention.

FIG. 3 is a diagram showing a manufacturing process of the semiconductor laser device according to the present invention.

FIG. 4 is a view illustrating a manufacturing process of the semiconductor laser device following FIG. 3;

FIG. 5 is a diagram showing a configuration example of a cooling device for a semiconductor laser device using a Peltier effect device which has been conventionally used.

FIG. 6 is a diagram showing a structure of a conventional semiconductor laser device.

[Description of Signs of Main Parts]

101 ··· Substrate 102 ··· p-InP cladding layer 103, 105 ··· Guide layer 104 ··· Active layer 106 ··· n-cladding layer 107 ··· Contact layer 108 109a, 109b, 109c Electrode 120 Semiconductor laser element 201 Chip carrier 202 Solder 203 Insulator 204 Metal conductor 210 Semiconductor laser device 301 p-InP substrate 302, 304 InGaAsP guide layer 303 InGaAsP active layer 305 n-InP clad layer 306 n-InGaAsP 307 ··· n-InGaAs contact layer 308 ··· mask 309 ··· insulators 310 and 311 ··· ... Electrode films 311a, 311b, 311c ... Electrode 501 ... Semiconductor laser element 502,504 ... Heat dissipation member 503 ... Peltier effect element 601 ... 602 p-clad layer 603 605 guide layer 604 active layer 606 n-clad layer 607 contact layer 608 609

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kiyofumi Takema 6-1-1, Fujimi, Tsurugashima-shi, Saitama Pref.

Claims (6)

[Claims] 1. A semiconductor laser device having a Peltier effect device incorporated in a semiconductor laser device. 2. The semiconductor laser device comprises: a substrate and a p-type layer made of a p-type semiconductor material; an active layer; an n-type layer made of an n-type semiconductor material; and an electrode. 2. The semiconductor laser device according to claim 1, wherein said semiconductor laser device is formed on said n-type layer. 3. The semiconductor laser according to claim 2, wherein said electrode comprises an electrode for flowing a current for driving a semiconductor laser element, and an electrode for flowing a current for driving a Peltier effect element. element. 4. The semiconductor laser device according to claim 2, wherein said n-type layer comprises an n-type cladding layer and an n-type contact layer. 5. An electrode surrounding the n-type cladding layer for flowing a current for driving a semiconductor laser device has an endothermic effect,
5. The semiconductor laser device according to claim 4, wherein the periphery of the electrode through which a current for driving the Peltier effect element flows has a heat radiation effect. 6. A method for manufacturing a semiconductor laser device, comprising: a substrate and a p-type layer made of a p-type semiconductor material;
a step of laminating an n-type layer made of an n-type semiconductor material, a step of forming a ridge in the n-type layer, and a step of passing a current for driving a semiconductor laser element on the n-type layer after the ridge is formed. Forming an electrode and an electrode through which a current for driving a Peltier effect element flows.