JPS62222690A - Semiconductor laser and manufacture thereof - Google Patents

Abstract

PURPOSE:To obtain a photoelectron integrated circuit consisting of a film having easy film-thickness controllability and excellent crystallizability by forming a current constriction layer for a semiconductor laser on the same layer with an active layer. CONSTITUTION:An N-type GaAs buffer layer 2 and an N-type AlGaAs clad layer 3 are shaped onto an N-type GaAs substrate 1 through an organo metallic chemical vapor deposition method in succession. An I-type GaAs current construction region 5 and an N-type GaAs active region 4 are shaped simultaneously through the organo metallic chemical vapor deposition method, vertically irradiating the growth substrate by an excimer laser selectively as the growth substrate is left as it is positioned in a reaction pipe, and a P-type AlGaAS clad layer 6 and a P-type GaAs cap layer 7 are formed through the organo metallic chemical vapor deposition method. An Au-Ge electrode 8 and an Au-Cr electrode 9 are each shaped to the N-type GaAs substrate 1 and the P-type GaAs cap layer 7 through an evaporation method.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a structure of a semiconductor laser and a method of manufacturing the same.

[Conventional technology]

Conventionally, as described in Japanese Unexamined Patent Publication No. 57-49289, the active layer and the current confinement layer were formed of different layers.

[Problem that the invention seeks to solve]

However, the current confinement layer of a conventional semiconductor laser is epitaxially grown separately from the active layer, and is formed by performing an etching process or a thermal diffusion process.

Formation technology using an etching process has the problem that when the substrate during semiconductor laser manufacturing is removed from the reaction chamber for etching, the grown film becomes contaminated and crystal defects occur at the interface with the cladding layer or gap layer. .

In addition to the above-mentioned problems, the formation technology using the thermal diffusion process described above also has the problem that the diffusion time is long and the crystallinity of the light-emitting part deteriorates due to high-temperature treatment.

The present invention aims to solve these problems, and its purpose is to make the current confinement layer and the active layer the same layer and manufacture it in one step without performing an etching process or a thermal diffusion process. .

[Means for solving problems]

The semiconductor laser of the present invention is characterized in that the structure of the semiconductor laser includes a current confinement layer for suppressing the lateral spread of current, wherein the current confinement layer is the same layer as the active layer. A method for manufacturing a semiconductor laser is characterized in that a current confinement region and an active region are formed in one step by a metal organic vapor phase epitaxy method in which a semiconductor wafer is selectively irradiated with an excimer laser.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view showing the basic structure of this type of planar stripe laser. Buffer Jfj 2, n-type AAGα
Next, the Ascla/D layer 3 is sequentially formed by metal-organic vapor phase epitaxy. Next, while the growth substrate is placed in the reaction tube, an excimer laser is selectively irradiated perpendicularly to the growth substrate, and the organic By metal vapor phase epitaxy, an i-type G (HAs current confinement region 5 and an n-type GaAl1 active region 4 are formed simultaneously, and a p-type AQGaAs cladding layer 6 and a p-type G
a A 8 Cap layer 7 is formed by metal organic vapor phase epitaxy. The n-type GaAs substrate 1 and the p-type GaAs cap layer 7 are each coated with Au-Go electrodes IJj8 by vapor deposition.
and Au-0r? ! ! Form pole 9.

By forming planar stripes in this way,
The current that flows when a voltage is applied with the Au-Ge electrode 8 as negative and the Au-0r electrode 9 as positive is i-type GαA.
Since the s1li flow is blocked by the constriction region 5, n-type GαA
8 are concentrated in an extremely narrow width passing through the active region 4. Therefore, the width of the region where laser oscillation occurs becomes extremely narrow, and as a result, a decrease in threshold current and single-transverse mode oscillation can be easily obtained.

However, in this case, the width of the region where laser oscillation occurs is uniquely determined by the width of the n-type GαA8 active region 40.

Conventionally, the width of the n-type GaAs active region 4 has been formed using an etching method or a thermal diffusion method.

Therefore, the outer mold G (the width of the IA11 active region 4 and the n-type G
The steepness of the interface between the aAs active region 4 and the i-type GαAB current confinement region 5 varies from laser chip to laser chip, which makes it difficult to obtain devices with good characteristics at a high yield. The widths of the current confinement region and the active region can be precisely controlled using the method, and by forming the interface steeply, the uniformity of each laser chip can be improved and the yield can be increased.

Figure 2 shows the change in carrier density depending on the presence or absence of excimer laser irradiation using metal-organic vapor phase epitaxy. The solid line shows the case without excimer laser irradiation, and the broken line shows the case with excimer laser irradiation. In the present invention, by using the 11M ratio shown by A in FIG. 2, the outer mold Gα
The As active region 4 and the i-type G (!A11 current confinement region 5) were grown in one step.

FIG. 3 is a cross-sectional view showing the process of forming an n-type GaAs active region 4 and an i-type G(lA8) current confinement region 5. The growth substrate is irradiated with an excimer laser 11 perpendicularly to the irradiated area using a mask 10. Epitaxial growth is performed with selectivity.

The outline of the present invention has been explained above using a G(lA8-AAGaAs semiconductor laser).However, other Z-V compounds can be manufactured using this manufacturing method as well;
It is also possible to use 11-W compounds such as n S e % Z n S. It is also possible to perform epitaxial growth with active region 4 in FIG. 1 as P type and current confinement region 5 as i type using the same manufacturing method. It is.

In addition, in the actual example, the excimer laser was irradiated perpendicularly to the growth substrate, but growth can also be performed by irradiating not only vertically but also at any angle.0 [Effects of the Invention] As described above According to the present invention, since the structure of the semiconductor laser is flat, the film thickness can be easily controlled and a film with good crystallinity can be grown. easy.

Moreover, the active region and current confinement region can be created in just one epitaxial growth, reducing the number of steps.Furthermore, since there is no need for an etching process, the grown layer can be manufactured without ever taking it out of the reaction tube, which prevents contamination of the grown layer and further heats it up. Since there is no need for a diffusion process, there is no crystallinity deterioration in the light emitting part that tends to occur with high-temperature processing, and the time required for the process can be significantly shortened.Furthermore, the excimer laser can control the variation and steepness of the dimensions of the active region, resulting in good characteristics. devices can be manufactured in large quantities with good yield, the number of workers can be reduced, and the devices can be manufactured at low cost.

[Brief explanation of drawings]

FIG. 1 is a perspective view of a semiconductor laser according to the present invention, FIG. 2 is a diagram of changes in carrier density depending on the presence or absence of excimer laser irradiation, and FIG. 3 is a main sectional view of active layer formation. 1...1 type GaA3 substrate 4...n type GaA3 active region 5...i type G (IAsN, flow constriction region 11...
・・・Excimer laser and above Figure 1 Figure 2

Claims (2)

[Claims] (1) A semiconductor laser having a structure including a current confinement layer for suppressing the lateral spread of current, characterized in that the current confinement layer is the same layer as the active layer. (2) A method for manufacturing a semiconductor laser, comprising an epitaxial growth step using metal organic vapor phase epitaxy, and a step of irradiating a substrate with an excimer laser during the epitaxial growth step.