JPH0690064A - Manufacture of semiconductor laser element - Google Patents

Abstract

PURPOSE:To provide a method for manufacturing a semiconductor laser element which can improve reliability by eliminating the distortion of a buried layer. CONSTITUTION:A mesa-stripe-shaped part in <011> or <0-11> direction where a first conductive type compound semiconductor clad layer 12, an active layer 13, and a second conductive type compound semiconductor clad layer 14 are laminated successively is formed on the surface of a first conductive type compound semiconductor substrate 11, then the side surface of the mesa-stripe-shaped part is buried successively by a second conductive type compound semiconductor current rejection layer 15 and a first conductive type compound semiconductor current block layer 16 while leaving an upper-edge part by the organic metal vapor growth (MOCVD) method, and then a second conductive type compound semiconductor clad layer 17 is laminated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to metal organic chemical vapor deposition (M
The present invention relates to a method for manufacturing a semiconductor laser device using the OCVD method.

[0002]

2. Description of the Related Art A conventional buried type semiconductor laser device is manufactured in the following steps using, for example, a metal organic chemical vapor deposition (MOCVD) method. That is, 1) The n-InP buffer layer 2, the multiple quantum well active layer 3, and the p-InP clad layer 4 are sequentially stacked on the n-InP substrate 1 (FIG. 2A). 2) Next, a selective growth mask 9 made of a dielectric film such as SiN _x is formed on this wafer by using a photolithography technique, and then the n-InP buffer layer 2 is formed using this selective growth mask 9. To form a mesa (FIG. 2B). 3) Next, p-InP current confinement layer 5 and n are formed on both sides of the mesa.
—Laying the InP current constriction layer 6 (FIG. 2C). 4) Next, the selective growth mask 9 is removed, a p-InP clad layer 7 and a p-GaInAs contact layer 8 are laminated in order to obtain a flat surface and increase the contact surface with the electrode. Finally, the electrodes 9 and 10 are formed (FIG. 2D).
In this manufacturing method, the metal organic chemical vapor deposition (MOCVD) method is used three times.

[0003]

However, the method of manufacturing a semiconductor laser device as described above has the following problems. That is, when the current confinement layer is grown on the side surface of the etched mesa under the selective growth mask, strain is introduced into the current confinement layer by the mask, and the reliability of the semiconductor laser device is reduced.

[0004]

The present invention provides a method of manufacturing a semiconductor laser device which solves the above problems.
<011> or <0> in which a first conductivity type compound semiconductor clad layer, an active layer, and a second conductivity type compound semiconductor clad layer are sequentially stacked on the surface of the first conductivity type compound semiconductor substrate.
The mesa stripe shape portion in the −11> direction is formed, and then the second conductivity type compound semiconductor current blocking layer and the first conductivity type metal organic vapor phase epitaxy (MOCVD) method is used to leave the side surface of the mesa stripe shape portion at the upper end. It is characterized in that a type compound semiconductor current blocking layer is sequentially buried, and then a second conductivity type compound semiconductor clad layer is laminated.

[0005]

According to the present invention, in the metal organic chemical vapor deposition method, (11
1) It utilizes the phenomenon that an epitaxial layer is difficult to grow on the surface. That is, <011> or <0
When a mesa stripe shape portion in the −11> direction is formed and the side surface thereof is filled with a second conductivity type compound semiconductor current blocking layer, a second conductivity type compound semiconductor layer having a (111) plane is formed on the upper surface of the mesa stripe shape portion. Stack. Then the first
When the conductive type compound semiconductor current blocking layer is sequentially buried, the first conductive type compound semiconductor layer is not stacked on the second conductive type compound semiconductor layer on the upper surface of the mesa stripe shape portion. In this case, since the selective growth mask is not used, a strain-free current blocking layer can be formed. Therefore, when the second conductivity type compound semiconductor clad layer is laminated thereon, the pn reverse junction is formed on the side surface of the mesa stripe shape portion, but is not formed on the upper surface of the mesa stripe shape portion, and the injection current is applied to the mesa stripe shape portion. The upper surface can be narrowed.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the embodiments shown in the drawings. FIG. 1 is a process explanatory view of an embodiment of a semiconductor laser device according to the present invention, and the process is as follows. That is, 1) The n-InP buffer layer 12, the multiple quantum well active layer 13, and the p-InP clad layer 14 are sequentially laminated on the surface of the (100) n-InP substrate 11 by using the metal organic chemical vapor deposition method (FIG. 1 (a)). 2) Next, using a photolithography and etching technique on this wafer, height 2.5 μm, width 1.5 μm
To form a mesa stripe in the <011> direction (see FIG. 1).
(B)). 3) Next, a p-InP layer is stacked by a metal organic chemical vapor deposition method, a 2.0 μm-thick p-InP current blocking layer 15 is formed on the n-InP buffer layer 12, and p-InP is formed on the mesa.
The clad layer 15a is laminated. At this time, the growth of the p-InP clad layer 15a is stopped at a thickness of about 1 μm, and (11
1) It is a face. Then, an n-InP layer is laminated,
N with a height of 0.8 μm so that the top of the mesa is left on the side of the mesa
-InP current blocking layer 16 is laminated. At this time, n-In
The P layer is a p-InP clad layer 15 having a (111) plane.
It is not laminated on a. Then, p-InP clad layer 1
7. p-GaInAs contact layer 18 is laminated. According to the present embodiment, the number of vapor phase growth times is two. The compound semiconductor material is not limited to the above-mentioned embodiment,
Further, the conductivity types of p and n may be reversed.

[0007]

As described above, according to the present invention, the first conductivity type compound semiconductor clad layer, the active layer and the second conductivity type compound semiconductor clad layer are sequentially laminated on the surface of the first conductivity type compound semiconductor substrate. <011> or <0 −
11> direction mesa stripe shape part is formed, and then
By the metal organic chemical vapor deposition (MOCVD) method, the side surface of the mesa stripe shape part is sequentially filled with the second conductivity type compound semiconductor current blocking layer and the first conductivity type compound semiconductor current blocking layer, leaving the upper end portion, and then the second conductivity type. Since a type compound semiconductor clad layer is laminated, a mask for selective growth is not used, so there is no strain during buried growth, the device reliability is improved, and the number of vapor phase growth is reduced. It has an excellent effect.

[Brief description of drawings]

1A to 1C are process explanatory views of an embodiment of a method for manufacturing a semiconductor laser device according to the present invention.

2A to 2D are process explanatory views of a conventional method for manufacturing a semiconductor laser device.

[Explanation of symbols]

 11 n-InP substrate 12 n-InP buffer layer 13 multiple quantum well active layer 14 p-InP clad layer 15 p-InP current blocking layer 15a p-InP clad layer 16 n-InP current blocking layer 17 p-InP clad layer 18 p-GaInAs contact layer

Claims (1)

[Claims] 1. A first conductivity type compound semiconductor clad layer, an active layer and a second conductivity type compound semiconductor clad layer are sequentially stacked on a surface of a first conductivity type compound semiconductor substrate <011.
Of the second conductivity type compound semiconductor current blocking layer by forming a mesa stripe-shaped portion in the <> or <0-11> direction and then leaving the upper end portion on the side surface of the mesa stripe-shaped portion by a metal organic chemical vapor deposition (MOCVD) method. A method of manufacturing a semiconductor laser device, comprising: sequentially burying a first conductivity type compound semiconductor current blocking layer, and then stacking a second conductivity type compound semiconductor clad layer.