JPS6321286A - Epitaxy for compound semiconductor on substrates of different kinds - Google Patents

Abstract

PURPOSE:To mass-produce high-performance elements consisting of the title semiconductor crystal capable of preventing the warpage of a substrate at a low cost by growing a compd. semiconductor thin film on the buffer layers formed by growing a compd. semiconductor thin film on both faces of a specified single crystal substrate while removing a part of the layer. CONSTITUTION:A compd. semiconductor (e.g., amorphous GaAs) thin film is grown in the same thickness on both faces of the single crystal substrate consisting of Si or alpha-Al2O3, etc., to form buffer layers. The material is then set in a liq. phase epitaxial growth furnace, and the above-mentioned compd. semiconductor is successively grown on at least the one buffer layer while removing a part of the buffer layer by meltback. The material is worked, for example, and a light emitting diode having an excellent light emitting characteristic, etc., is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for epitaxially growing a compound semiconductor such as GaAs on a heterogeneous single crystal substrate such as St or α-Aj7203.

[Prior Art] Compound semiconductor devices such as GaAs are manufactured using liquid phase epitaxy (LPE), vapor phase epitaxy (VPE), and molecular beam epitaxy, except for FETs, ICs, etc. that are manufactured using ion implantation. (MBE) method or metalorganic chemical vapor deposition (
It is often created using an epitaxial growth method such as the MOCVD method.

Generally, the substrate and growth layer are, for example, GaAs/GaAs5
Similar crystals such as GaAs/GaAρAs or INP/INP are used. These substrates are SL substrates or α-Al2O3, which are the mainstream materials in the current semiconductor industry.
It has drawbacks such as being expensive, heavy, and difficult to increase in area.

Therefore, if a compound semiconductor such as GaAs can be epitaxially grown on a heterogeneous substrate such as Si, it will open the way to the realization of optical integrated circuits, solar cells for use in space satellites, power FETs, etc., with higher performance and lower cost. This technique is becoming possible with non-equilibrium epitaxial growth methods such as MBE and MOCVD, but is not possible in principle with equilibrium growth methods such as LPE.

However, there are problems in terms of reliability when creating optical devices, which is the most distinctive feature of compound semiconductors, using non-equilibrium growth methods such as MBE and MOCVD. has become the mainstream technology for creating optical devices.

Therefore, S
Growth of compound semiconductor on i-substrate and L on the growth layer
By combining high-quality crystal growth using the PE method, it becomes possible to create large-area solar cells, optical integrated circuits, etc. with excellent radiation resistance.

[Problems to be solved by the invention] However, in the case of LPE growth, the substrate must be flat, but when compound semiconductors are grown on a Si substrate by MBE or MO
The substrate grown by the CVD method has a large warpage due to the difference in thermal expansion coefficient between St and the compound semiconductor.
In reality, LPE growth was not possible.

[Object of the Invention] In view of the problems of the prior art described above, the present invention has been developed by growing a compound semiconductor by MBE growth or MOCVD on a heterogeneous substrate such as St.
It is an object of the present invention to provide an epitaxial growth method that allows LPE growth without causing warpage in the substrate even during D growth.

[Summary of the Invention] The present invention involves growing compound semiconductor thin films of the same thickness on both sides of a single crystal substrate such as Si or α-Ag203 to form a buffer layer, and forming a buffer layer on at least one of the buffer layers. The gist of this method is to grow a compound semiconductor thin film by LPE while removing a portion of the surface of the layer by meltback.

[Function] That is, by growing a compound semiconductor thin film of the same thickness on both sides of a single crystal substrate such as Si or α-A I 20a by MBE method or MOCVD method to form a buffer layer, Si Even if the thermal expansion coefficients of the substrate and the compound semiconductor are different, since there is a buffer layer of the same thickness on both sides of the substrate, the substrate will not warp, and therefore LPE growth can be performed on the buffer layer. It becomes possible.

[Example] Examples of the present invention will be described below.

Carrier concentration 5X1018cII with mirror polishing on both sides
1-3 Si single crystal substrate was annealed at 900℃ for about 5 minutes, and amorphous G was formed on both sides of the Si substrate at 450℃.
After MOCVD growing an aAs layer of about 100 μm and annealing this amorphous GaAs layer, 2 μm of n” GaAs layers to serve as buffer layers are grown on both sides of the substrate by MOCVD. In this way, the same thickness is grown on both sides of the Si substrate. By forming the GaAs layer, warpage of the substrate can be prevented.

This Si substrate was set in an LPE furnace, and an n” GaAs buffer layer was melted back to a thickness of 1 μm.
Etch and layer n GaAs on top with a thickness of 10 μm.
Ga Aρ As is grown by LPE to 10 μm sO, 70.3 p Ga A, 77 As is grown to 10 μm, and 0.7 0.3 p”GaAs is grown by 1 μm by LPE.

When this was processed to create a light emitting diode, good light emitting characteristics were obtained.

In addition, using α-A, 920a substrate, G was applied on both sides of the substrate.
MOCVD growth of aAs buffer layer with GaA on one side.
After LPE growth of S or InP, etc., it is processed to form GaA.
sIC can be formed.

In addition, in this example, M is used as a method for forming the buffer layer.
Although the OCVD method has been explained, the MBE method may also be used.

[Effect of the invention] As explained above, according to the present invention, SL or α-
Buffer layers are formed by MOCVD or MBE growth of compound semiconductor thin films of the same thickness on both sides of a single crystal substrate such as Al1203, and a part of the surface of the buffer layer is formed on at least one of the buffer layers. By growing the compound semiconductor thin film by LPE while removing it by meltback, there is no warpage on the substrate, and LPE growth, which has excellent mass productivity, has the remarkable effect that high-performance devices can be mass-produced at low cost. play.

Claims (1)

[Claims] (1) A buffer layer is formed by growing compound semiconductor thin films of the same thickness on both sides of a single crystal substrate such as Si or α-Al_2O_3, and the surface of the buffer layer is formed on at least one of the buffer layers. A compound semiconductor epitaxial growth method on a heterogeneous substrate, characterized by growing a compound semiconductor thin film by liquid phase epitaxial growth while removing a portion by meltback.