JPS62189719A - Method for growing compound semiconductor - Google Patents

Abstract

PURPOSE:To readily grow a uniform thin single crystal film which has less structural defects by growing a compound semiconductor layer of specific thickness on a compound semiconductor crystal substrate. CONSTITUTION:The same compound semiconductor is grown at a temperature not higher than 450 deg.C by a vapor phase growing MOCVD method or an epitaxial MBE method 200Angstrom or less thick on a compound semiconductor substrate as a buffer layer, and the same compound semiconductor epitaxially grown film is grown by the normal method on the buffer layer. Since the epitaxially grown film is laminated by an ordinary method on the buffer layer grown by the MBE method at 250 deg.C of substrate temperature and approx. 100Angstrom of film thickness, the adverse influence of substrate defects existing in semi-insulating LEC (Liquid Encapsulated Czochralski) GaAs semiconductor substrate can be reduced.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to a method for growing compound semiconductors, and in particular to a method for growing a single crystal thin film of high quality by reducing adverse effects originating from the substrate such as defects in the compound semiconductor crystal substrate (epitaxial growth). ).

(Prior art) "Semiconductor Epitaxy Technology" by Takashi, first edition, October 1980
30th, detailed in Sangyo Tosho. In general, in the growth method of compound semiconductors, the quality of the epitaxially grown film is sensitive to the condition of the substrate surface. An epitaxial film is grown on the surface of this substrate at a normal growth temperature.

(Problems to be Solved by the Invention) However, even epitaxially grown films grown by such a method have the problem that they are adversely affected by defects inherent in the compound semiconductor substrate, resulting in epitaxially grown films of poor quality. Ta.

The present invention improves the above-mentioned problems, uses the same compound semiconductor as the compound semiconductor substrate as a buffer layer, reduces the adverse effects of defects in this substrate, and grows a high-quality epitaxial film (problems Means for Solving Problems) The present invention removes damage on the surface of a compound semiconductor crystal substrate using wet etching or the like, cleans the surface by heat treatment, and performs metal organic chemical vapor deposition (MOCV).
D method) or molecular beam epitaxial growth method (MBE method), etc. are used to grow the same compound semiconductor as the substrate as a buffer layer on the substrate at a temperature of 450° C. or less to a size of 200× or less. This method is used to grow an epitaxially grown film of the same compound semiconductor as the substrate.

(Function) As described above, according to the present invention, the same compound semiconductor can be formed on a compound semiconductor substrate by MOCVD or MBE at a temperature of 450° C. or less! The compound semiconductor is grown under +200X and used as a buffer layer, and an epitaxially grown film of the same compound semiconductor is grown on this buffer layer by a normal method, thereby reducing the negative effects of substrate defects inherent in the compound semiconductor substrate. be able to.

(Example) The present invention will be explained in detail below.

First, a commercially available semi-insulating LEC (Liqu
id Encapsulated Czochrals
ki) Etching away the damaged layer on the surface of the GaAs semiconductor substrate using a sulfuric acid-hydrogen peroxide based etching solution. Next, this GaAs substrate is heated to 580° C. for about 5 minutes while irradiating Aa in an MBE apparatus to remove oxides on the surface of the GaAs substrate, thereby cleaning the substrate surface. The heating conditions at this time are set by confirming by electron beam diffraction that the surface structure of this substrate has a 2×4 lattice arrangement using a device such as RHEED.

Next, as a buffer layer, the substrate temperature is increased to 25% on the surface of this substrate.
GaAs is grown to a thickness of 100° C. by the MBE method at 0° C.

Subsequently, the MBE method is applied on this buffer layer to reduce the substrate temperature to 6.
A QBAs epitaxial growth film is grown under the conditions of 00°C, 1μ, and ty'H.

In the examples of the present invention, the MBE method is used as the growth method for the 74777 layer and the epitaxially grown film, but the MBE method is
Other epitaxial growth methods such as the VD method can be used. In addition, this buffer layer maintains a substrate temperature of 150 to 40°C in the MBE method and 400 to 45°C in the MOCVD method.
It can be formed at 0°C.

Furthermore, according to the embodiment of the present invention, since the GaAs substrate whose surface has been etched in advance is heat-treated while irradiating As, the surface can be cleaned without any burrs that would cause dissociation of As from the GaAs substrate. can. In addition, since the epitaxially grown film is laminated using a normal method on a buffer layer grown using the MBE method to a film thickness of approximately 100x at a substrate temperature of 250°C, adverse effects such as substrate defects inherent in the semi-insulating LEC GaAs semiconductor substrate may occur. can be reduced. Furthermore, embodiments of the present invention allow the buffer layer and epitaxial film to be grown sequentially in the same apparatus. In addition, in the embodiments of the present invention, since the substrate, buffer layer, and epitaxial film are made of the same material, the substrate may warp due to differences in expansion coefficients.
(Effects of the Invention) As described above in detail, according to the present invention, a uniform single crystal thin film with few structural defects can be easily grown. Therefore, a good and uniform compound semiconductor device can be obtained.

Patent applicant: Oki Electric Industry Co., Ltd. Procedural amendment (sealed) 1. Display of the case 1985 Patent Application No. 030983 2, Name of the invention Compound semiconductor growth method 3, Person making the amendment Relationship with the case Patent application Person's address (
105) 1-7-12-4, Toranomon, Minato-ku, Tokyo.
Agent address (105) 1-7-1 Toranomon, Minato-ku, Tokyo
No. 2 No. 6, Contents of amendment (1) In the 17th line of page 1 of the specification, the phrase "reduced quality" is amended to read "reduced quality".

(2) In the third to fourth lines of page 3 of the same book, the phrase "removed and heat treated" is amended to "removed and heat treated in a vacuum."

(3) “100λ thick” on page 4, line 15 of the same book.
Correct it to ``rloooλ thickness''.

(4) On the 18th line of the same page in the same book, “Temperature 600℃, 1μ
m/H" is corrected to "Temperature: 600° C., growth rate: 1 μm/H."

(5) On page 5, line 7 of the same book, the phrase ``GaAs substrate'' has been corrected to ``GaAs substrate.''

(6) On the 11th line of the same page of the same book, it says "Growth by 250℃...method".

Claims (1)

[Claims] A step of etching or heat treating the surface of a compound semiconductor crystal substrate to clean the surface;
A method for growing a compound semiconductor, comprising the steps of growing a layer of the compound semiconductor with a thickness of 0 Å or less, and then growing a crystal of the compound semiconductor on the thin film at a normal growth temperature.