JPS6170781A - Semiconductor laser and manufacture thereof - Google Patents

Abstract

PURPOSE:To position a laser chip easily to a chip mount precisely, and to improve the yield of a semiconductor laser by using a mark displaying a beam projecting section as a reference when the laser chip is positioned to the chip mount. CONSTITUTION:Notches 8b, 9b formed by patterns are each shaped to electrodes 8a, 9a. The notches 8b, 9b represent beam projecting sections for a chip 1a, and measure the size of squares of 1-5mum so as not to have an effect on the luminescent function of the chip 1a, and the positions of the notches coincide with a light-emitting section 3 on a plan view for the chip 1a. Consequently, the chip 1a can be positioned to the chip mount 10 while using the notches 8b or 9b and positioning marks 11 as references, thus accurately enabling positioning easily. The electrodes 8a, 9a are shaped in a wafer 12 on which a plurality of chips 1a are arranged and formed to a matrix shape.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a semiconductor laser and a method for manufacturing the same, and particularly relates to an improvement in the chip structure thereof.

Semiconductor lasers have come to be frequently used as optical signal sources in optical communications and information processing that use light as a medium and handle large amounts of information.

As a type of optical information processing, for example, in DAD, etc.
In order to obtain good coupling between the semiconductor laser serving as a light source and the lens, it is important that the light emitting part of the semiconductor laser is accurately positioned at a predetermined position.

Therefore, it is desirable to be able to accurately and easily align the position when attaching the laser chip.

[Conventional technology]

FIG. 2(A) is a perspective view showing a typical example of a conventional semiconductor laser chip. The chip 1 is n% (or p type)
On the substrate 2, there are a light emitting section 3 made of a striped active layer whose end becomes a light emitting section, a p-type (or n-type) craft layer 4, and a p-type (or n-type) contact layer 5. Ohmic electrodes 6.7 are provided above and below, and electrodes 8.9 are further formed above and below the ohmic electrodes 6.7.

The size of the chip 1 is about 300 μm in length and width, about 100 μm in thickness, the width of the light emitting part 3 is about 3 μm, and the width of the electrode 8.9 is about 250 μm.

The chip 1 is shown in FIG. 2 (B) to form a semiconductor laser.
) As shown in the figure, it is aligned and mounted on a chip mount 10 which is a heat sink or mount.

[Problem that the invention seeks to solve]

The alignment of the chip 1 with respect to the chip mount 10 should be performed based on the light emitting part 3 of the chip 1 and the alignment mark 11 of the chip mount 10, but since the light emitting part 3 is generally difficult to see, On the chip 1 side, the width of the electrode 8 or 9 on the side not joined to the chip mount 10,
Alternatively, it is performed based on the outer shape of the chip 1.

However, the width of the electrode 8.9 or the outer shape of the chip 1, for example, the center position may not always match the position of the light emitting part 3, and the light emitting part 3
The matching becomes inaccurate, and the semiconductor laser using the above-mentioned chip 1 has a problem of low yield.

[Means for Solving the Problems] The above problems are solved by the semiconductor laser of the present invention, in which the laser chip is provided with a mark indicating the light emitting part, and further according to the present invention, the mark is The problem is solved by the manufacturing method of the present invention, which is formed by a pattern of electrodes formed on the main surface of the knob, and in this case, when forming the electrode, the mark provided on the electrode is aligned with the striped light emitting part. Ru.

[Effect]

When aligning the laser chip with respect to the chip mounting base, accurate alignment is facilitated by using the mark indicating the light emitting part as a reference, and using the electrode width or chip outer shape as mentioned earlier as a reference. It becomes possible to eliminate the conventional inconvenience caused by this.

In addition, when the mark is formed by the pattern of the electrode, the position of the core matches the position of the striped light emitting part by the manufacturing method described above, and the core accurately indicates the light emitting part of the chip. It becomes like this.

This alignment of the marks is possible when forming the electrode on the side of the substrate that has the light emitting part.

Even if the position of the light emitting part is difficult to see, it can be made visible by etching the path from the bottom to the ground layer to a depth of several μm. This is because only a portion of the wafer formed by arranging a plurality of chips in a matrix can be processed.

In addition, when providing a similar mark on the electrode formed on the substrate side, the cough mark is aligned with the above-positioned mark to be aligned with the light emitting part, and this mark also accurately aligns the light emitting part. It comes to show.

Thus, with the configuration of the present invention, it is possible to improve the yield of semiconductor lasers compared to the conventional method.

〔Example〕

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

FIGS. 1(A-1) and 1(A-2) are a perspective view and a plan view showing one embodiment of a semiconductor laser chip according to the present invention;
Figure (B) is a plan view showing the attachment of the chip to the chip mounting base, and Figures 1 (C-1) and (C-2) are perspective views showing alignment during electrode formation in the manufacture of the semiconductor laser. It is a diagram.

FIG. 1 (A-1) is a diagram corresponding to FIG. 2 (A), and the illustrated chip 1a has electrodes 8.
It is changed to a. The electrodes 8a, 9a are provided with cutouts 8b, 9b formed by patterns, respectively.

These notches 8b and 9b are marks indicating the light emitting part of the chip 1a, and have a size of 1 to 5 μm square so as not to affect the light emitting function of the chip 1a, and are shown in FIG. 1 (A-2). In the plan view of the chip 1a shown, the position coincides with the light emitting section 3.

Therefore, the alignment of the chip 1a with respect to the chip mount 10 in FIG. 1(B) shown similarly to FIG. Therefore, the positioning can be performed more accurately and easily than in the past.

The positions of the notches 8b and 9b can be matched with the position of the light emitting part 3 as shown in FIG. 1 (A-2) by the following manufacturing method.

That is, the formation of the electrodes 8a and 9a is as shown in FIG. 1 (C-1).
(C-2) As shown in the figure, the pattern of the electrode 8a when forming the electrode 8a is
To align the pattern 8d of the notch 8b, the one in the upper front of the notch 8b and the one in the back (not shown) are aligned with the corresponding positions of the light emitting parts 3 (see FIG. 1 (C-1)), and then Pattern 9c of electrode 9a when forming electrode 9a
The pattern 9d of the notch 9b is aligned in the same way.
What is necessary is to align the position of the notch 8b with the position of the notch 8b (see FIG. 1 (C-2)).

In addition, when aligning the electrode 8a pattern, if the position of the light emitting part 3 is difficult to see, the electrode 8a pattern on the wafer 12
The etching can be made visible by etching the path from the a-forming side to the craft layer 4 to a depth of several μm, so the above-mentioned etching can be performed on the area of the wafer 12 necessary for the alignment.

〔Effect of the invention〕

As explained above, according to the configuration of the present invention, there is provided a semiconductor laser and a method for manufacturing the same, which can more accurately and easily align the laser chip when attaching the laser chip to the chip mounting base than before. This has the effect of making it possible to improve the yield of the semiconductor laser compared to the conventional method.

[Brief explanation of drawings]

In the drawings, FIGS. 1(A-1) and 1(A-2) are a perspective view and a plan view showing one embodiment of a semiconductor laser chip according to the present invention, and FIG. 1(B) is a chip mounting base of the chip. 1 (C-1) and (C-2) are perspective views showing alignment during electrode formation in the manufacture of the semiconductor laser, and FIG. 2 (A) is a conventional FIG. 1B is a perspective view showing a typical example of a semiconductor laser chip. FIG. 1B is a plan view showing how the chip is attached to a chip mount. In the figure, 1.1a is a chip, 2 is a substrate, 3 is a light emitting part, 4 is a cladding layer, 5 is a contact layer, 6.7 is an ohmic electrode, 8.8a, 9
．． 9a is an electrode, 8b and 9b are notches, 8c and 9c are electrode patterns, 8d and 9d are notch patterns, 10 is a chip mounting base, 11 is an alignment mark, and 12 is a wafer.

Claims (3)

[Claims] (1) A semiconductor laser characterized in that a laser chip is provided with a mark indicating a light emitting part. (2) The semiconductor laser according to claim 1, wherein the mark is formed by a pattern of electrodes formed on the main surface of the chip. (3) A method for manufacturing a semiconductor laser, characterized in that when forming an electrode on the main surface of a laser chip, a mark provided on the electrode to indicate a light emitting part is aligned with a striped light emitting part. .