JPH0669108B2 - Semiconductor laser and manufacturing method thereof - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor laser and a method for manufacturing the same, and more particularly to improvement of a chip structure thereof.

Semiconductor lasers have come to be widely used as optical signal sources for optical communication and information processing that handle a large amount of information using light as a medium.

As one of optical information processing, for example, in a DAD or the like, it is important that the position of the light emitting portion of the semiconductor laser is precisely at a predetermined position so that a good coupling between the semiconductor laser as a light source and the lens can be obtained. is there.

Therefore, it is desirable that the position of the laser chip can be accurately and easily adjusted when the laser chip is attached.

[Prior Art] FIG. 2A is a perspective view showing a typical example of a chip of a conventional semiconductor laser. The chip 1 is an n-type (or p-type)
On the substrate 2, there are a light emitting portion 3 having a striped active layer and an end portion thereof serving as a light emitting portion, a p-type (or n-type) clad layer, and a p-type (or n-type) contact layer 5, and above and below thereof. Are provided with ohmic electrodes 6 and 7, and electrodes 8 and 9 are formed above and below them.

And the size of the chip 1 is about 300 μm in length and width and about 100 in thickness.
The width of the light emitting portion 3 is about 3 μm, and the width of the electrodes 8 and 9 is about 250 μm.

In order to form a semiconductor laser, the chip 1 is aligned and mounted on a chip mounting base 10 which is a heat sink or mount base as shown in FIG. 2 (B).

[Problems to be solved by the invention]

The alignment of the tip 1 with respect to the tip mount 10 is
Positioning mark 11 between the light emitting part 3 of the chip 1 and the chip mount 10
Generally, the light emitting unit 3 should be used.
Since it is difficult to visually recognize, on the chip 1 side, it is performed with reference to the width of the electrode 8 or 9 on the side not bonded to the chip mount 10 or the outer shape of the chip 1.

However, the widths of the electrodes 8 and 9 or the outer shape of the chip 1, for example, the center position, may not always match the position of the light emitting unit 3, and the light emitting unit 3 may be inaccurately aligned with the alignment mark 11. The semiconductor laser using the chip 1 has a problem of low yield.

[Means for solving problems]

According to the present invention, the above-mentioned problems are caused by the present invention, in which electrodes formed on the upper and lower surfaces of a chip in which stripe-shaped light emitting regions are formed in the front and rear are provided in the electrode end portions corresponding to the light emitting portions on the front and rear end faces of the light emitting region. By providing a mark having a width smaller than that of the light emitting portion of the chip, and also in the wafer in which the chips having the light emitting regions in stripes are arranged in parallel in a matrix at appropriate intervals, the wafer surface When patterning the electrodes of each chip by forming an electrode film on each of the chips, there are marks corresponding to the light emitting parts at the front and rear ends of each chip On the wafer to the positions of the front-end front end and the rear-end rear end of the light emitting part facing the light emitting part of the chip, and patterning the electrode film to form electrodes for each chip. It is solved Te.

[Action]

When aligning the laser chip with the chip mount, accurate alignment is facilitated by using the mark indicating the light emitting portion as a reference, and the electrode width or the chip outer shape described above is used as a reference. This makes it possible to eliminate the conventional inconvenience.

Further, when the mark is formed by the pattern of the electrode, by the above-described manufacturing method, the position of the mark coincides with the position of the stripe-shaped light emitting portion, and the mark accurately indicates the light emitting portion of the chip. Like

The position of this mark can be adjusted in forming the electrode on the side having the light emitting portion with respect to the substrate.

Even if it is difficult to visually recognize the position of the light emitting portion, it can be visually recognized by etching a depth of about several μm from the side to the cladding layer. This is because it is sufficient to perform only a part of the wafer formed by arranging a plurality of chips in a matrix.

Note that when a similar mark is provided on the electrode formed on the substrate side, the mark is aligned with the above-described positioned mark to be aligned with the light emitting portion, and this mark also accurately indicates the light emitting portion. As shown.

Thus, the structure of the present invention makes it possible to improve the yield of semiconductor lasers as compared with the conventional one.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. The same reference numerals denote the same objects throughout the drawings.

1 (A-1) and 1 (A-2) are a perspective view and a plan view showing an embodiment of a semiconductor laser chip according to the present invention, and FIG. 1 (B) is a mounting of the chip on a chip mounting base. FIGS. 1 (C-1) and 1 (C-2) are perspective views showing alignment during electrode formation in the manufacture of the semiconductor laser.

FIG. 1 (A-1) corresponds to FIG. 2 (A). In the illustrated chip 1a, the electrodes 8 and 9 of the chip 1 are replaced with electrodes 8a and 9a. The electrodes 8a and 9a are provided with notches 8b and 9b formed by a pattern, respectively.

The notches 8b and 9b are marks showing the light emitting portion of the chip 1a, and are 1 to 5 μm so as not to affect the light emitting function of the chip 1a.
It has a size of a corner and is aligned with the light emitting portion 3 on the plan view of the chip 1a shown in FIG. 1 (A-2).

Therefore, the positioning of the chip 1a with respect to the chip mounting base 10 shown in FIG. 1B shown in FIG. 2B is performed with reference to the notch 8b or 9b and the positioning mark 11. Therefore, the alignment can be performed more accurately and easily than in the past.

It is possible to match the positions of the notches 8b and 9b with the position of the light emitting section 3 as shown in FIG. 1 (A-2) by the following manufacturing method.

That is, the formation of the electrodes 8a and 9a is carried out by forming (C-1) and (C-
2) As shown in the figure, since it is performed on the wafer 12 formed by arranging a plurality of chips 1a in a matrix, the pattern 8c of the electrode 8a when forming the electrode 8a is aligned with the pattern 8d of the cutout 8b. In the figure, one on the front side and one on the back side (not shown) are respectively aligned with the corresponding positions of the light emitting section 3 (see FIG. 1 (C-1)), and the pattern 9c of the electrode 9a when the electrode 9a is formed thereafter. For the position alignment, the pattern 9d of the cutout 9b may be aligned with the position of the cutout 8b in the same manner (see FIG. 1 (C-2)).

In addition, when aligning the electrode 8a pattern, the light emitting unit 3
When the position of is difficult to visually recognize, it becomes visible by etching a depth of approximately several μm from the side where the electrode 8a is formed on the wafer 12 to the cladding layer 4, so that the region necessary for the alignment of the wafer 12 is obtained. Then, the above etching may be performed.

〔The invention's effect〕

As described above, according to the configuration of the present invention, there is provided a semiconductor laser and a method of manufacturing the same that can more accurately and easily align the chip when mounting the laser chip on the chip mount. There is an effect that the yield of the semiconductor laser can be improved and the yield of the semiconductor laser can be improved as compared with the conventional case.

[Brief description of drawings]

In the drawings, FIGS. 1 (A-1) and (A-2) are a perspective view and a plan view showing an embodiment of a semiconductor laser chip according to the present invention, and FIG. 1 (B) is a chip mount of the chip. FIG. 1 (C-1) and (C-2) are perspective views showing alignment during electrode formation in the manufacture of the semiconductor laser, and FIG. FIG. 2B is a perspective view showing a typical example of a semiconductor laser chip, and FIG. 2B is a plan view showing how the chip is mounted on the chip mounting base. In the figure, 1, 1a is a chip, 2 is a substrate, 3 is a light emitting part, 4 is a clad layer, 5 is a contact layer, 6 and 7 are ohmic electrodes, 8, 8a, 9 and 9a are electrodes, 8b, 9b is a notch, 8c and 9c are electrode patterns, 8d and 9d are notch patterns, 10 is a chip mount, 11 is an alignment mark, and 12 is a wafer.

Claims (2)

[Claims] 1. A chip having a striped light emitting region formed in front and back thereof, which is attached to both upper and lower surfaces of a chip, wherein light emission of the chip is provided at an electrode end corresponding to a light emitting portion at a front and rear end face of the light emitting region. A semiconductor laser characterized in that a mark having a width smaller than that of the portion is provided. 2. A wafer in which chips each having a stripe-shaped light emitting region are arranged in parallel in parallel with each other at appropriate intervals in a matrix form, an electrode film is formed on the wafer surface, and electrodes of each chip are patterned. At this time, the front row front end and the front row front end facing the light emitting section of the chip on the wafer and the front end of the front row of the electrode mask pattern having a mark corresponding to the front and rear light emitting sections of each chip A method of manufacturing a semiconductor laser, comprising forming an electrode for each chip by patterning an electrode film in accordance with the position of the light emitting portion at the rear end of the last row.