JPS627700A - Vapor phase epitaxial growth method for compound semiconductor - Google Patents

Abstract

PURPOSE:To grow epitaxially a high-purity compd. semiconductor by etching and removing the epitaxially grown compd. semicondcutor on a single element semiconductor substrate and the heat-treating the substrate at an appropriate temp. CONSTITUTION:An Si substrate 11 as the single element semiconductor substrate is pretreated with hot HNO3 and impurities 12 on the surface are removed as much as possible. Then a compd. semiconductor consisting of GaAs 13 is epitaxially grown on the substrate 11 by using AsH3 and Ga(CH3)3. The GaAs 13 is subsequently removed by gas etching along with the impurities 12 with use of a reactive gas such as AsCl3. Then the Si substrate 11 with the exposed surface free of impurities is heat-treated at >=900 deg.C to rearrange the several atomic layers on the surface and then a compd. semiconductor consisting of GaAs 14 is again epitaxially grown.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to an improvement in a method for vapor phase epitaxial growth of a compound semiconductor on a single element semiconductor substrate.

(Prior art and its problems) In recent years, light-emitting devices, light-receiving devices, and high-speed field-effect transistors using ■-v group compound semiconductors have been put into practical use and widely used. On the other hand, single-element semiconductors, especially Si,
A logic circuit IC'pLSN using Ge or the like is also widely used. Recently, research has been conducted to grow compound semiconductors on single-element semiconductors, with the aim of developing opto-electronic integrated devices that take advantage of the characteristics of these two types of semiconductor devices and have new functions. . Looking at this kind of research from a different angle, we believe that the use of single-element semiconductor substrates, which are much cheaper than compound semiconductor substrates, is likely to lead to lower prices for optoelectronic integrated devices in the future. be able to.

Recently, a vapor phase growth method for growing GaAs on a relatively good quality GaAs t-8i substrate has been reported (Japanese Journal of Applied Physics).
se Journal of Applied Phys.
sics), Vol. 23, No. 11, 1984, L843-L
845 pages).

In this method, HP chemical etching is performed as a pretreatment of the Si substrate, and then the substrate is placed in a growth reaction tube, and
Heat treatment is performed at 0°C or higher for 10 minutes while flowing group V gas (in this case, AlH3), and then at a low temperature (400 to 450°C).
GaAs is grown at a normal temperature (700°C). However, the table shows that according to this method, impurities such as qFe, Ni, and Cu adhere to the surface of the single-element semiconductor substrate after pretreatment.

It is difficult to remove these impurities simply by heat treatment at high temperatures, and the impurities are incorporated into the compound semiconductor grown on the substrate. As described above, there is a drawback that the purity of the grown original compound semiconductor changes depending on the pretreatment method of the substrate and the cleanliness of the surface, and as a result, the luminescence characteristics of the grown film are also affected.

(Objective of the Invention) An object of the present invention is to provide a vapor phase growth method for epitaxially growing a high-purity compound semiconductor on a single-element semiconductor substrate, regardless of the pretreatment method of the single-element semiconductor substrate. , Sru.

(Structure of the Invention) The vapor phase epitaxial growth method of the present invention is a vapor phase growth method in which a compound semiconductor is grown epitaxially on a single element semiconductor substrate, in which a compound semiconductor is grown on a single element semiconductor substrate, and then a compound semiconductor is grown on a single element semiconductor substrate. Etch and remove the semiconductor.

After that, the elemental semiconductor substrate is subjected to heat treatment at t-900°C or higher, and then the compound semiconductor is grown again t-Ijf!
It is assumed to be f-symptom.

(Detailed explanation of configuration) According to the vapor phase epitaxial growth method of the present invention.

Many impurities that have adhered to the surface of the single-element semiconductor substrate after pretreatment and cannot be removed by the pretreatment are incorporated into the compound semiconductor that is initially grown. After that, the compound semiconductor is completely removed, and a single-element semiconductor substrate surface free of impurities appears. The halide-based gas hardly etches the single-element semiconductor substrate even at high temperatures, so the substrate surface will not be roughened or a surface damage layer will be formed.Furthermore, the surface-purified substrate is then heat-treated at 900°C or higher. As a result, several atomic layers on the surface of a single-element semiconductor undergo a surface rearrangement phenomenon that facilitates the subsequent growth of a compound semiconductor.As described above, according to the growth method of the present invention, the problem that occurred with the conventional technology is caused. The film quality of the grown compound semiconductor is not affected by the pretreatment conditions of a single-element semiconductor substrate, which is rare, and a grown film of high purity can be obtained.

(Example) Hereinafter, it will be explained in detail using the drawings. Figure 1 is.

FIG. 3 is a process diagram of an embodiment of the present invention. The attempted vapor phase growth apparatus was a low-pressure organometallic vapor phase growth apparatus (L) with a reaction tube as the machine plate.
P-MOCVD). An 8i substrate is selected as the single element semiconductor substrate 11, and the growth plane orientation is (100) plane ±o, s.
'6 was used. First, as a pretreatment for the substrate 1, the substrate 11 was boiled and poured 9 HNOsKa times to remove as much dirt and impurities 12 on the surface as possible, and then washed with water and dried (first
Figure 1a)). Immediately place the 8i substrate 11 into the LP-MOCVD reaction tube.

Set the pressure to 100 Torr in H2 atmosphere and apply normal G
Similar to the time of aAs growth, 700 while flowing human sH3f.
The temperature is raised with C1, and trimethyl gallium (T
GaAs 13 was grown to a thickness of 50 nm as a metallurgical compound semiconductor using MG; Ga (CH3) a (FIG. 1 Φ)). Then, AsCp was used as a reactive gas.
, st was removed by gas etching (FIG. 4(C)). Then A s H3
Immediately raise the temperature of the substrate 11 to 900° C. while flowing a ft. heat treatment for 5 minutes. After that, the temperature dropped to 700℃.

GaAs 14 was epitaxially grown to a thickness of 3 μm (FIG. 1(d)). At that time, the growth rate of GaAs 14 is 0
．． It was 8 μm/h. The surface of the obtained GaAs 14 is 1,,,A,,7. Eyoo 1□tsu. □44o,.

. . □:・d/V-8 was obtained.

Subsequently, the same experiment was performed by changing the pretreatment method for the Si substrate 11. One was etched with HF for 1 minute, and the other was etched with a glacial acetic acid mixture containing 9 elements.

I etched it for 3 minutes and prepared it. As described above, GaA grown on ft and 8i substrates 11 after 3wi type pre-treatments was performed.
When we investigated the photoluminescence characteristics of 7jGaAs grown on a GaAs substrate, there was no difference in the photoluminescence intensity at 77K. The strength of G a As grown on the 8i substrate is about 5-6 lateral roots, which is significantly improved. Moreover, no difference was observed due to the difference in pretreatment, and the effects of the present invention could be fully confirmed.

In this example, Si was used as the single element semiconductor substrate and the compound semiconductor 1GaAs was used, but the present invention is not limited thereto. GaP, I
It can also be applied to the case where multicomponent mixed crystals such as nP, InGaAsP, and AllGaAs, and II-VI group compound semiconductors are provided. Furthermore, in this example, a low-pressure organometallic vapor phase epitaxy apparatus is used as the vapor phase epitaxy apparatus, but there is no need to be limited to this, and an atmospheric pressure organometallic vapor phase epitaxy apparatus or a halide-based vapor phase epitaxy apparatus may also be used. .

Furthermore, the reactive gas is not limited to AsCl13, but HCl
t.

Other reactive etching gases such as C, 112, Br, I2, etc. may also be used.

(Effects of the Invention) As described in detail above, the vapor phase epitaxial growth method of the present invention has advantages over conventional growth methods.

The film quality of the grown compound semiconductor can be easily obtained with good reproducibility, regardless of the substrate pretreatment method or conditions. Furthermore, the luminescence intensity of the film is stronger than that obtained by conventional methods, and a highly purified grown film can be obtained.

[Brief explanation of drawings]

FIGS. 1(a) to 1d) are cross-sectional views for explaining the growth process of an embodiment of the present invention. 11...8i substrate, 12... impurity, 13.14...
GaAs.

Claims (1)

[Claims] A step of epitaxially growing a compound semiconductor on a single-element semiconductor substrate, and etching and removing the grown compound semiconductor using a reactive gas,
1. A method for vapor phase epitaxial growth of a compound semiconductor, comprising the steps of heat treatment at a temperature of at least .degree. C. and the step of epitaxially growing a compound semiconductor again on the substrate after the heat treatment.