JPS58147188A - Semiconductor laser device - Google Patents

Abstract

PURPOSE:To obtain a semiconductor laser which has no variation in the thermal resistance at the junction between an element and a heat sink, heat dissipation and good reliability by composing electrodes arranged on an N type conductive region side of metal members having good adhesive strength to an insulating film. CONSTITUTION:An insulating film 3 made of SiO2 is covered on a compound semiconductor substrate 1 made of P type conductive PbSSe, the center is removed by etching in a stripe shape, with the film 3 as a mask an N type conductive region 2 is formed by a diffusing method. A gold (Au) deposited stripe electrode 21 which is electrically connected is formed onto the striped active region, a chromium (Cr) film 22 having excellent bonding strength with the film 3 is covered by a deposition method. The formed semiconductor laser element is fixed via indium (In) 7 on the heat sink base 6 made of Cu through the chromium film 22.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field of the Invention The present invention relates to an improvement in the electrode structure of the side fixed to a heat sink of a semiconductor laser element whose active region has a striped structure.

('b) Prior art and problems Conventional semiconductor lasers with a stripe structure include, for example, p-conductivity type lead, sulfur, and selenium (PbS), as shown in Figure 1.
N conductivity type region 2 on compound semiconductor substrate 1 made of Se)
An insulating film 8 such as Sing is selectively formed on a surface other than the surface to be formed by a vapor deposition method, and using the insulating film 8 as a mask, stripe-shaped n-conductivity type regions are formed on the substrate l by a diffusion method. 2, the nst type region 2 of the substrate 1 is formed.
Gold (Au) electrodes 4.
5. A laser device, that is, a planar fiber type semiconductor laser device is fabricated. Furthermore, the semiconductor laser device configured in this manner is mounted on a heat sink base 6 made of copper having high thermal conductivity as shown in the figure, in order to dissipate the heat generated at the junction during operation and to achieve good continuous oscillation of the laser beam τ. The structure is connected to the n-conductivity type region 2 and fixed with indium (In) 7 via a nine-metal electrode.

By the way, in the conventional semiconductor laser device having the above-mentioned configuration, the adhesion strength between the gold electrode 4 provided on the side of the mold region 2 and the insulating film 8 is weak, so the gold electrode 4 is placed on the heat sink base 6. As a result, the oscillation threshold current of the laser beam increases and the oscillation wavelength changes at the bonding surface between the gold electrode 4 and the insulating film 8, which causes the element to be fixed thereon. Furthermore, in extreme cases, the heat sink base 6 and the heat sink element may be completely peeled off, which is an undesirable inconvenience.

(Q) Purpose of the Invention The present invention has been made in order to eliminate the above-mentioned drawbacks, and its purpose is to provide an electrode disposed on the n-conductivity type region surface side of a semiconductor laser device with good adhesion to an insulating film. It is an object of the present invention to provide a novel semiconductor laser device which is constructed from a dangerous metal member, has a dangerous change in thermal resistance at the junction between the element and a heat sink base, and has good heat dissipation and reliability.

Shun) Structure of the invention ,′.

That is, the present invention provides a semiconductor laser device having a striped active region, in which an electrode is formed that is electrically connected to the active region, and is in contact with the upper surface of the electrode and on an insulating film on the surface of the device substrate. forming an extended chrome layer,
It is characterized in that the laser element is fixed to a heat sink via the chrome layer.

(e) Embodiments of the Invention Preferred embodiments of the invention will be described in detail below with reference to the drawings.

FIG. 2 is a schematic perspective view showing an embodiment of a semiconductor laser device according to the present invention, and the same parts as in FIG. 1 are given the same reference numerals. In the figure, 1 is, for example, PbSS of p-conductivity type.
2 is a compound semiconductor substrate consisting of E, and 2 is an insulating film 8 made of 5iOs+ deposited on the substrate l, and the central part of the insulating @S is removed by selective etching in a stripe shape.
The n-conductivity type region is formed by a diffusion method using the insulating film 8 as a mask, and the electrode 21 electrically connected to the n-conductivity type region 8, that is, the striped active region, is made of gold (as shown in the figure). Au) is deposited in a stopophe pattern by vapor deposition. □ is in contact with the upper surface of the stripe electrode 21 and on the entire surface of the element substrate l.
A chrome (Or) film 22 having excellent adhesion strength to the insulating film 8 is deposited via the insulating film 11118 by vapor deposition or the like.

5 is a gold electrode provided on the surface of the substrate IIs.

The semiconductor laser wire thus constructed is fixed to the heat sink base 6 made of Cu through the chrome 22 with indium (In) 7, so that the stripe electrode 21 and the chrome A fatal failure such as the film 2g peeling off from the element substrate 1 as in the conventional case does not occur, and heat dissipation and oscillation characteristics are greatly improved.

(f) Effects of the Invention As is clear from the above explanation, the structure of the semiconductor laser device according to the present invention improves the adhesive strength between the semiconductor laser element and the heat sink base, and significantly reduces the contact thermal resistance between them. Therefore, it is possible to obtain a highly reliable semiconductor laser device with a nutripe structure, such as a semiconductor laser device with good heat dissipation and stable oscillation characteristics. Therefore, it is of course applicable not only to the planar fiber type semiconductor laser device made of PbSSe thread explained in this embodiment, but also to buried stripe type or mesa stripe type semiconductor laser devices using various compound semiconductors. It has nine excellent effects.

[Brief explanation of the drawing]

FIG. 1 is a schematic perspective view showing the structure of a conventional planar stripe type semiconductor laser device, and FIG. 2 is a schematic perspective view showing an embodiment of the semiconductor laser device according to the present invention. In the figure, 1 is a p4w type compound semiconductor substrate, 2 is a striped n-conductivity type region (active region), 8 is an insulating film, and 5 is a p4w type compound semiconductor substrate.
is a gold electrode, 6 is a heat sink base, 7 is indium, 2
Reference numeral 1 indicates a stripe electrode, and reference numeral 22 indicates a chrome film.

Claims (1)

[Claims] In a semiconductor laser device having a striped active region, a chromium layer is provided which forms an electrode electrically connected to the active region, and which is in contact with the upper surface of the electrode and extends over an insulating film on the surface of the device substrate. What is claimed is: 1. A semiconductor laser device comprising: a chromium layer formed thereon;