JPS61115365A - Semiconductor element - Google Patents

Abstract

PURPOSE:To prevent deterioration due to heat generation by forming constitution in which a melting-in to a growth layer of an internal current constriction layer is prevented. CONSTITUTION:A GaAs layer 5 is shaped so that a p type GaAlAs clad layer 6 is grown easily in a liquid-phase manner. A GaAlAs layer 4 obviates the melting-in of an n type GaAs layer 3 into the p type GaAlAs clad layer 6 when the layer 6 grows. The melting-in of Ga1-xAlxAs to a Ga solution reduces with the increase of x. Accordingly, when the p type GaAlAs clad layer 6 grows on the GaAs layer 5, a melting-in more than the GaAs layer 5 melts into the layer 6 is prevented by the GaAlAs layer 4 under the layer 5 though the GaAs layer 5 melts into the layer 6.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Object of the Invention [Field of Industrial Application] The present invention relates to a QaAs-QaAIAs semiconductor element having an internal current confinement layer, which is found in semiconductor lasers and the like.

[Prior art]

A conventional semiconductor element having an internal current confinement layer consists of a semiconductor substrate, an internal current confinement layer formed on the substrate and partially removed by etching, and a liquid-phase growth layer formed on the internal current confinement layer by a liquid phase growth method. It is composed of various growth layers to be grown.

[Problem that the invention seeks to solve]

In conventional semiconductor devices that have a current confinement layer inside, it is often seen that the current confinement layer melts into adjacent grown layers during the manufacturing process in which various growth layers are formed on the current-like 5i layer. . By the way, the grown layer adjacent to this current confinement layer generally has a conductivity type opposite to that of the current confinement layer, so when such penetration occurs, the electron concentration decreases due to the compensation effect, and the grown layer becomes high. Become a resistance. When a current is passed through this element, this high-resistance layer generates heat, which causes the element to deteriorate.

In addition, such weld penetration does not occur uniformly on the bonding surface, so the channel shape is not made uniform, which causes variations in the performance of the device.

This invention was made in view of the above circumstances, and it is possible to prevent the current confinement layer from penetrating into the growth layer, thereby providing a semiconductor element that does not deteriorate due to heat generation and has uniform performance. This is what we provide.

(b) Structure of the invention The configuration of this invention will be explained using FIG. 1.

In the semiconductor element (101), (102) is a semiconductor substrate, (103) is various growth layers, (104) is between the semiconductor substrate (102) and various growth layers (103),
GaAs layer (105), GaAlAs layer (106)
This current confinement layer is composed of three layers: , Ga As layer (107).

The operation of this configuration will be explained next.

GaAs layer (105) forming the first current confinement layer,
GaAlAs layer (106) and GaAs layer (107)
The layer that mainly constricts the current is a GaAs layer (10
7). Ga As N (105) is provided so that the growth layer (103) formed thereon can be easily grown in a liquid phase. The GaA1As layer (106) is
When the growth layer (103) grows, the GaAs layer (107)
) is infiltrated into it and prevents it from changing the composition of the grown layer (103). The thickness of the GaAs layer (105) must be such that even if all of it melts into the growth layer, no effect will be caused.

Further, the GaA1As layer (105) is the GaAs layer (107).
) must be formed to a thickness that does not melt into the growth layer (103). In this way, in the present invention, G
Since the aAs layer (107) is prevented from penetrating into the grown layer (103), the non-uniformity of the static and dynamic characteristics of the semiconductor element due to the conventional dispersion of penetration is eliminated.
The performance and characteristics of the device are made more uniform, and the high resistance of the layer, which is caused by the mixing of layers of different conductivity types, is eliminated, and the quality of the device is improved.

〔Example〕

The present invention will be described in detail below based on embodiments applicable to semiconductor lasers. Note that this invention is not limited to this.

In Figure 2, (1) is a semiconductor laser, (2)
is a p-type GaAs substrate with an n-type GaAs layer (3) on top of it.
A current confinement layer is formed of a GaAlAs layer (4) and a GaAs layer (5). (6) is a GaAs layer (5)
(7), (81, (9)) are GaAj!As active layers grown on top of the p-type GaAlAs cladding layer grown by liquid phase growth, (7), (81, (9)) and n-type Ga
They are an AJAs cladding layer and an n-type GaAs capping layer.

In this configuration, G a A s JW (5) is p
Type GaAj! An As cladding layer (6) is provided in the container so as to be grown in a liquid phase. GaAl1As layer (4
) prevents the n-type GaAs layer (3) from penetrating into the p-type GaAj2As cladding layer (6) when it grows. By the way, Ga1-xAn for Ga solution!
The melting of xAs decreases as X increases. Therefore, the p-type GaA6As cladding layer (6) is c a A
When growing on the s-layer (5), the GaAs layer (5) is grown on top of the s-layer (5).
) may penetrate, the underlying GaAlAs layer (4) will prevent further penetration.

Here, in the n-type GaAs layer (3), the channel depth is limited to about 1.5 micrometers due to current confinement, so the donor concentration is more than l X I Q ''/cd, and the barrier thickness is At 0.3 micrometer or more, 1.
A value of 5 micrometers or less is required. Also, G a A
The s layer (5) is p-type GaA7! As cladding layer (6
), even if all of it dissolves into it, p-type Ga
In order to reduce the influence on the AJAs cladding layer (6), it is desirable that the layer be non-doped and have a thickness of 0.1 micrometer or less.
lW<4) is Cat-xA to prevent the aforementioned melt penetration.
It is preferable that It may be the same as the As cladding layer (6), and the layer thickness of the GaAlAs layer (4) must be at least 0.05 micrometer to prevent melt penetration.

Note that the lateral confinement of the light of the semiconductor laser (1) is
p-type GaAj! As cladding layer (6) and GaAj? A.S.
Since it is determined by the thickness of each layer (4), GaA
The layer thickness of the l1As layer (4) is determined from p-type GaAj! to obtain the necessary laser characteristics. As cladding layer (6)
It is the value obtained by subtracting the layer thickness.

In this way, the semiconductor laser in this example is
Since melt penetration into the growth layer of the current confinement layer is prevented, deterioration due to resistance heat generation is prevented, and non-uniformity in performance caused by variations in melt penetration is eliminated.

(c) Effects of the invention According to this invention, 4. Since the internal current confinement layer is prevented from penetrating into the growth layer, deterioration due to heat generation is prevented, and non-uniformity in performance affected by the degree of penetration is eliminated, resulting in a long life and production yield. A high quality semiconductor device is provided.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the structure of the present invention, and FIG. 2 is a block diagram showing one embodiment of the present invention. (ll-・-semiconductor laser, (2)---p-type Ga
As substrate, (3)-n-type GaAs layer, (41-Ga
A I As layer, (5)-Ga As layer, (
61-f) type GaAl1As cladding layer, (
71-G a A I As active layer, (81-1-n
type GaAJAs cladding layer, (91---n type GaAs
cap layer.

Claims (1)

[Claims] 1. A current confinement layer is provided between the semiconductor substrate and various growth layers, and the current confinement layer includes a GaAs layer, a GaAlAs layer, and a G
A semiconductor device comprising three layers including an aAs layer.