JPH0846284A - Semiconductor laser pellet - Google Patents

Abstract

PURPOSE:To correct the defective mounting and bonding in the assembling step by a method wherein a long protrusion is provided along an insulating film formed side on the surface of a metallic film near said side for preventing an insulator from bonding onto the surface of the electrode metallic film of a pellet or narrowing the bonding area for avoiding any defective mounting and bonding. CONSTITUTION:In order to form an insulating film 17 on the side of a pellet 10, a bar substrate 12 of a semiconductor layer is held between spacers 11 so as to form the insulating film 17 on the sides 13a, 13b of the insulating film 17 by sputtering step. At this time, if a protrusion 15a is formed on the electrode metallic film 14 on the surface of the pellet 10, no sputtered insulator will be bonded onto the shade 16a of the protrusion of a sputter source. Successively, the insulating film 17 is formed likewise on the opposite insulating film formed surface 13b. At this time, if another protrusion 15b is formed, any sputtered insulator will not be bonded onto the shade 16b of the sputter source.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION This invention relates to the structure of semiconductor laser pellets.

[0002]

2. Description of the Related Art A pellet of a conventional semiconductor laser device will be described with reference to a plan view a and a side view b shown in FIG. The semiconductor laser pellet is Cr / A on the surface of the InP substrate 42.
It has a surface electrode metal film 44 of five layers of u / Ti / Pt / Au. The back surface has a six-layer back surface electrode metal film 45 of Au / Ge / Au / Ni / Ti / Au. An insulating film 46 is formed on the two insulating film forming side surfaces 43 of the pellet which face each other. In the process of manufacturing the semiconductor laser pellet, the electrode metal film (44, 45) is formed on the InP substrate 42 according to the present invention.
A method of forming an insulating film of silicon oxide, silicon nitride, or the like on the side surface of the pellet by sputtering after forming is described. After forming the electrode metal films (44, 45) in a wafer state in order to form the insulating films on the two side surfaces of the pellet facing each other,
The side surface of the insulating film is shown, and several tens of pellets are connected to each other to be cleaved into a bar (bar-shaped substrate). The following will be described with reference to FIG. Bar-shaped substrate 2 of the semiconductor laser
The spacers 1 having substantially the same size and shape are alternately stacked with the insulating film formation side surfaces 3 aligned. At this time, the bar-shaped substrate 2
The side surface 3 of the insulator to be sputtered and the side surface of the spacer 1 are aligned and superposed so as to be flush with each other. The spacer 1 and the bar-shaped substrate 2 thus superposed are mounted on a vapor deposition jig 8 and held by a pressing spring 9 so that no gap is created in the superposed portion 4. In this state, an insulator is sputtered on the insulator forming side surface 3 to form an insulating film. Subsequently, an insulating film is formed on the opposite side surface by the same process. The bar-shaped substrate 2 on which this insulating film is formed is cleaved into individual semiconductor laser pellets.

[0003]

Since the surface of the bar-shaped substrate 2 of the semiconductor laser has undergone the etching process, a small gap may be formed on the mating surface with the spacer 1. In addition, when the spacer 1 for sputtering and the bar-shaped substrate are superposed on each other, a gap is created even if a foreign matter enters.
Insulators during sputtering enter this gap and adhere to the surface of the electrode metal film of the semiconductor laser pellet. There is a problem that the insulator attached to the surface hinders the mountability and the bondability in the subsequent assembling process and causes a defective assembly.

[0004]

According to the present invention, there is provided a semiconductor laser pellet having an insulating film formed on a side surface thereof, wherein a long protrusion along the insulating film forming side surface is formed on a metal film surface in the vicinity of the insulating film forming side surface. It is a semiconductor laser pellet provided.

[0005]

According to the above semiconductor laser pellet, when the insulating film is formed on the side surface of the pellet, the convex portion near the sputter side surface of the metal film surface shields the sputtered insulator, and the convex portion shadows the sputter source. Insulation does not adhere to the inside. Further, the convex portion on the surface of the electrode metal film closes the gap when it comes into contact with the spacer at the time of stacking and prevents the insulative substance from entering the inside.

[0006]

Embodiment 1 An example of the present invention is shown in FIG. 2a is a plan view and FIG. 2b is a side view. The semiconductor laser pellet is I
A five-layered surface electrode metal film 25 of Cr / Au / Ti / Pt / Au is provided on the surface of the nP substrate 21, and the uppermost Au layer is a stripe-shaped recess 24 parallel to the insulating film formation side surface 23.
It has a convex portion 22. At this time, the insulating film 27 side is provided with the convex portion 2
5 is desirable. The back side is Au / Ge / Au / N
Having a six-layer back electrode metal film 26 of i / Ti / Au,
An insulating film 27 is formed on the two insulating film forming side surfaces 23 of the pellet which face each other. The manufacturing method of the pellet of the present invention,
The back electrode metal film 26 is formed on the InP substrate 21 of the semiconductor laser wafer by vapor deposition or sputtering. Further, five layers of the surface electrode metal are formed by vapor deposition or sputtering, and then Au plating is performed to obtain a thickness, so that the surface electrode metal film 25 is formed. Next, a stripe-shaped concave portion 24 and convex portion 22 are formed on the surface electrode metal film 25 in parallel with the insulating film formation side surface 23 by photoresist (not shown) and etching (not shown). The stripe width and the step of each of the concave portion 24 and the convex portion 22 are selected in consideration of the effect on the problem and manufacturing restrictions. Further, the stripe widths of the concave portion 24 and the convex portion 22 do not have to be the same, and may be changed depending on the position of the pellet. Next, in order to form the insulating films 27 on the insulating film forming side surfaces 23 of the two facing pellets on the wafer, after forming the electrode metal films (25, 26) in the wafer state, the wafer is placed on the insulating film forming side surfaces. Representation It is cleaved into a bar shape (bar-shaped substrate) with dozens of pellets connected. FIG. 1 shows a state of a gap between the bar-shaped substrate and the spacer when the bar-shaped substrate of the semiconductor laser of the present invention is superposed on the spacer and an insulator is sputtered on the side surface. The bar-shaped substrate 12 of the semiconductor laser is sandwiched between the spacers 11 and an insulating film is formed on the insulating film formation side surface 13a by sputtering (the same as the method described in the conventional technique). At this time, the electrode metal film 1 on the pellet surface
When the convex portion 15a is formed in 4, the sputtered insulator does not adhere to the shadow 16a of the convex portion with respect to the sputtering source. Subsequently, an insulating film is similarly formed on the opposing insulating film formation surface 13b by sputtering. At this time, if the convex portion 15b is formed on the electrode metal film 14 on the surface of the pellet,
The sputtered insulator does not adhere to the shadow 16b of the convex portion on the sputter source.

[0007]

Second Embodiment Another example different from the first embodiment of the present invention is shown in FIG. 3a is a plan view and FIG. 3b is a side view. The semiconductor laser pellet is formed of Cr / Au / T on the surface of the InP substrate 31.
Having a five-layer surface electrode metal film 32 of i / Pt / Au,
The peripheral portion 33 of the uppermost Au layer is thicker than the inside 34. The back surface has six layers of back electrode metal film 35 of Au / Ge / Au / Ni / Ti / Au. An insulating film 37 is formed on the two opposing insulating film forming surfaces 36 of the pellet. The method for manufacturing pellets according to the present invention is based on In
The back electrode metal film 35 is formed on the P substrate 31 by vapor deposition or sputtering. Further, five layers of the surface electrode metal are formed by vapor deposition or sputtering, and then Au plating is performed to thicken the four peripheral sides to form the surface electrode metal film 32. At the time of this plating, a plating condition (plating solution composition including Au concentration, stirring of plating solution, anode metal shape, plating temperature, voltage waveform including polarity, current density, etc.) is selected to form an electrode metal film 32 having a thickened electrode peripheral portion. Form. Next, in order to form insulating films on two side surfaces of the pellet on the wafer which face each other, the electrode metal film (32, 35) is formed in a wafer state.
After the formation, the side surface of the insulating film is shown, and several tens of pellets are connected to each other and cleaved into a bar (bar-shaped substrate).
The method of forming the insulating film 37 on the insulating film forming side surface 36 and the effects of the present invention are the same as those in the first embodiment.

[0008]

According to the present invention, the adhesion of the insulating material to the surface of the electrode metal film of the pellet is eliminated or the adhesion area is reduced to eliminate mounting defects and bonding defects during assembly, or at least greatly reduce them. .

[Brief description of drawings]

FIG. 1 is a side view of a state in which a gap between a bar-shaped substrate and a spacer of the present invention is present.

FIG. 2 is a plan view and a side view of a stripe-shaped electrode metal film surface pellet of the present invention.

FIG. 3 is a plan view and a side view of a convex pellet around the surface of an electrode metal film of the present invention.

FIG. 4 is a plan view and a side view of a conventional pellet.

FIG. 5 is a perspective view of a method for forming an insulator on the side surface of a pellet.

[Explanation of symbols]

 10 Pellet 13a, 13b, 23, 36 Insulator formation side surface 14, 25, 32, 34 Electrode metal film 15, 22, 33 Convex part 24 Recessed part 17, 27, 37 Insulating film

Claims (3)

[Claims] 1. A semiconductor laser pellet having an insulating film formed on a side surface thereof, wherein a convex portion long along the insulating film forming side surface is provided on a metal film surface near the insulating film forming side surface. 2. A semiconductor laser pellet having an insulating film formed on its side surface, wherein the electrode metal film is provided with stripe-shaped irregularities parallel to the side surface on which the insulating film is formed. 3. A semiconductor laser pellet having an insulating film formed on a side surface thereof, wherein a convex portion is provided on four peripheral sides of an electrode metal film.