JPH02257687A - Manufacture of semiconductor laser chip - Google Patents

Abstract

PURPOSE:To reduce the generation of fine stepped cracks, and to improve yield by bending a semiconductor-laser crystal substrate along the linear edge section of a jig in the direction of cleavage along a cleavage flaw formed on the end face of the substrate and communicating with a rear from a surface. CONSTITUTION:A cleavage flaw 2 communicating with a rear from a surface is shaped to the end face of the crystal substrate 1 of a GaAlAs semiconductor laser, and held and fixed from both surfaces by an extensible sheet 3, the flaw 2 is formed along the linear edge section of a jig 4 along the direction of cleavage of the cleavage flaw 2, and the semiconductor laser crystal substrate 1 is bent vertically in the direction of cleavage. An optical axis is hardly displaced in a semiconductor laser chip acquired in this manner, and the displacement of the optical axis is concentrated near a central optical axis. Accordingly, fine stepped cracks are drastically reduced, thus improving characteristics.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to a method for manufacturing a semiconductor laser chip.

(Prior art) Semiconductor lasers, which are small, robust, and have excellent wavelength purity and spatial uniformity of light, are used for reading compact discs (CDs) and video discs (VDs) as pickup light sources, and have been put into practical use. ing. It is also being put into practical use as a light source for optical files for writing purposes.

On the other hand, semiconductor lasers are used as light sources for laser printers and optical communications by taking advantage of their optical output density, unity, and high-speed response.

FIG. 4 shows a conventional method for manufacturing a semiconductor laser chip.

Conventionally, a semiconductor laser crystal substrate 41 is cut in a cleavage direction 4 from a cleavage wound 43 using a sharp knife (surgical scalpel) 42.
4, the crystal substrate is torn like splitting bamboo to obtain a laser chip 41a.

In addition, in FIG. 4, 45 is a semiconductor laser crystal substrate 4.
1, an end surface 46, a front surface, 47 a back surface, 48 a cutting direction, 49 an inter-fold surface, 50 a laser side cross section, and 51 a laser beam output direction.

(Problem to be solved by the invention) Conventionally, since the semiconductor laser crystal substrate was torn with a knife, the force was concentrated at one point, and it was difficult to apply force uniformly and continuously. Due to the force applied to the optical axis, cracks with minute differences in level occur, which causes the optical axis to shift.

The present invention provides a method for solving the above-mentioned problems, which makes it possible to easily form a semiconductor laser chip, significantly reduces microstep cracks, and
The purpose is to improve the characteristics.

(Means for Solving the Problems) The present invention provides a semiconductor laser crystal substrate with a cleavage scratch reaching the back surface on the front surface thereof, and fixing the cleavage scratch by sandwiching it from both sides with a stretchable sheet. The semiconductor laser crystal substrate is bent along the straight edge of the jig along the cleavage direction perpendicular to the cleavage direction.

(Function) A cleavage scar is provided on the end face of the semiconductor laser crystal substrate, extending from the first surface to the back surface, and in the shearing direction along the cleavage scar, the substrate is bent all at once along the straight edge of the jig to form the pleats. As a result, the occurrence of micro step cracks is significantly reduced.

(Example) Next, the interfold method according to the present invention will be described based on FIGS. 1 to 3, with some reference to FIG. 4.

FIG. 2 shows G a A Q A s to which the present invention is applied.
This figure shows a cross-sectional view of the structure of a semiconductor laser.
- On the GaAs layer 11, a current confinement layer 12, a p-cladding layer 13. Active layer 14. An n-cladding layer 15 and a contact layer 16 are each formed.

The A f2 As mixed crystal ratio of each layer is x = Or 0.
5y 0.08tO, 5, 0, 64, and the film thicknesses are t = l, Q, 0.2°0008.2.0.2, respectively.
There are approximately 0 households. AuGe or Au is vacuum-deposited as the n-side electrode 17, and a pattern serving as a guide between the folds is formed. To facilitate inter-folding, the p-GaAs layer was
Thin to about 0/ffi. A as the n-side electrode 18
UZn is vacuum deposited to form an ohmic electrode at a high temperature of 400°C.

Next, the inter-fold method of the present invention will be explained with reference to FIGS.
Attach the s-layer from the growth layer (front side) to the back side (it is not good if it does not reach the back side) 5. Next, place the substrate 1 (41 in Figure 4) between the two bendable sheets 3. sandwiched between
The cleavage scar 2 and the cleavage direction of the substrate are made to coincide with the edge of the jig 4 having a radius of curvature of about 5+m+, and the substrate is folded to form pleats from the cleavage scratch in the cleavage direction at once.

The semiconductor laser chip manufactured in this way is shown in Figure 3 (
As shown in a), compared to the figure (b), the optical axis deviation is smaller and concentrated near the central optical axis. Note that N=163
indicates the number of chips tested.

Although the present invention has been described with respect to a Ga A 12 A S crystalline substrate, it goes without saying that it can also be applied to other crystalline materials such as InGaAsP type and Pb5nTe type crystals.

(Effects of the Invention) As described above, in the present invention, a cleavage scar is provided on the end face of a semiconductor laser crystal substrate that extends from one surface to the back surface, and in the cleavage direction along the cleavage scar, the cleavage is performed along the straight edge of the jig. Since the sheet is folded and folded all at once, the occurrence of minute step cracks is reduced to about 1/10 of the conventional method, and not only is the work carried out quickly, but the yield of the product is significantly improved.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the inter-fold method according to the present invention, FIG. 2 is a cross-sectional view of the structure of a semiconductor laser, FIG. 3 is a diagram showing a comparison of optical axis deviations, and FIG. 4 is a diagram showing the conventional method. 1... Semiconductor laser crystal substrate, 2... Cleavage scratch,
3...Sheet, 4...Jig. 11... p-GaAs layer, 12... current confinement layer. 13...P-cladding layer, 14...active layer. 15...n-cladding layer, 16... contact layer,
17... n-side electrode, 18... p-side electrode. Patent applicant: Matsushita Electric Industrial Co., Ltd.

Claims (1)

[Claims] A cleavage wound that reaches the back surface is made on the front surface of the semiconductor laser crystal substrate, and it is held and fixed from both sides with a stretchable sheet, and then it is attached to the straight edge of the jig along the cleavage direction of the cleavage wound. A method for manufacturing a semiconductor laser chip, comprising bending a semiconductor laser crystal substrate perpendicular to a cleavage direction.