JPS63215089A - Manufacture of semiconductor laser - Google Patents

Abstract

PURPOSE:To dispense with flaws for cleavage as well as to reduce the noise due to the reflection of laser light from the bottom surfaces of grooves by a method wherein, after the grooves for forming reflective surfaces are formed by etching, grooves for cleavage are each formed on the bottom parts of the, grooves by, etching. CONSTITUTION:A clad layer (omitted in the diagram), an active layer 5 and a contact layer (not shown in the diagram) are grown on a substrate and thereafter, a pattern is formed of a resist in such a way that etching grooves make a right angle with a laser luminescence surface and an etching is performed to form laser reflective surfaces 2. After the resist is removed, a resist is again applied and an etching is performed to form V-shaped grooves 3. After the resist is removed, a passivation film and an electrode (not shown in the diagram) are formed and chips are separated by separation surfaces 4 by cleavage to obtain semiconductor lasers. According to such a way, the noise due to the reflection of laser radiation from the bottom surfaces of the grooves is reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method of manufacturing a semiconductor laser device used as a light source for various electronic devices and optical devices.

Conventional technology Conventionally, in the manufacture of semiconductor lasers, the reflective surface of the laser is
It is formed by cleavage of crystals. According to this manufacturing method, the laser devices can only be inspected after the devices within the wafer are individually separated, which poses a major challenge for mass production. Another problem is that it is difficult to integrate other elements on the same wafer.

In recent years, as a method to solve these problems, a method of forming a reflective surface of a semiconductor laser by wet etching or dry etching has been devised, and an etched cavity (
(hereinafter referred to as ICG) laser. This device has the function of a semiconductor laser on a wafer, so it can be inspected on a wafer and can be integrated with other devices.

Problems to be Solved by the Invention However, when the reflective surface 2 is formed by etching, the bottom surface of the etched groove 1 becomes flat, as shown in FIG. In order to separate it, it is necessary to make a scratch in the center of the bottom of groove 1. Further, the width of this flat portion is generally several tens of microns, and there is a problem that during laser operation, a part of the laser emitted light is reflected at the bottom surface and interferes with the emitted light, resulting in noise.

In order to solve the above-mentioned problems, the method for manufacturing a semiconductor laser device of the present invention includes forming a reflective surface by etching, and then applying wet etching or dry etching to the bottom of the groove created by etching. It is constructed by forming a V-groove.

Function: With this configuration, it is not necessary to make scratches for cleavage in the manufacturing process of the EC semiconductor laser, and it is also possible to reduce noise caused by reflection of laser light from the bottom surface of the groove formed by etching.

EXAMPLES Hereinafter, examples of the present invention will be described with reference to the drawings.

FIG. 1 is a schematic cross-sectional view of a semiconductor laser wafer formed by a method for manufacturing a semiconductor laser device according to an embodiment of the present invention. In FIG. 1, after growing a cladding layer (not shown in the figure), an active layer 6, and a contact layer on a substrate, a resist pattern is formed so that the etching groove is perpendicular to the laser emitting surface. /H2o
Etching was performed for 3 minutes using a 1/8/1 etching solution to form a laser reflecting surface 2. After removing the resist, apply the resist again, H2SO4/H2O2/H20=1/8
/8 etching solution for 40 seconds to create V groove 3.
was formed. Thereafter, the resist was removed, a passivation film and electrodes were formed, and then the chips were separated at the separation plane 4 by cleavage and assembled as a semiconductor laser.

At the time of cleavage during chip separation, it was possible to cleave smoothly without damaging the wafer. Further, FIG. 2 shows FFP of laser light in Example a of the present invention and in Case b without V-groove, and the noise due to reflection from the bottom surface is significantly reduced by the present invention.

Effects of the Invention As described above, the present invention can be used to manufacture an EC semiconductor laser by further forming a V-groove at the bottom of the etched portion, thereby eliminating the need to make scratches for wafer cleavage in advance, and furthermore, by forming a V-groove at the bottom of the etched portion, there is no need to make scratches for wafer cleavage in advance. It is possible to reduce noise caused by reflection of laser light.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a semiconductor laser device according to an embodiment of the present invention, and FIGS. 2a and 2b are FFP of a semiconductor laser according to an embodiment of the present invention and an FFP of a conventional EC semiconductor laser
FIG. 3, which shows the FP, is a cross-sectional view of a conventional KG semiconductor laser. 1... Etching groove, 2... Laser reflection surface, 3... V groove, 4... Chip separation surface, 6... Active layer.

Claims (1)

[Claims] After forming each layer including the active layer on the semiconductor wafer, a first groove was formed by etching to form a reflective surface, and a V-shaped second groove was formed at the bottom of the groove by etching. A method for manufacturing a semiconductor laser device, characterized in that the second groove is then cleaved.