JPH01234390A - Production of gallium arsenic layer and production of gallium arsenic-aluminum gallium arsenic laminate - Google Patents

Abstract

PURPOSE:To obtain a GaAs layer having exactly desired compsn. ratios and excellent film quality by forming the GaAs layer on a silicon substrate at a low temp. by using a molecular ray epitaxy method, then irradiating As molecular rays and Al molecular rays thereto to form an AlAs single atom layer thereon and further subjecting said film to a specific heat treatment. CONSTITUTION:The GaAs layer having no crystal defects is formed on the silicon substrate at the low temp. of 350-580 deg.C by using the molecular ray epitaxy method and thereafter, the layer is irradiated by the As molecular rays and the Al molecular rays for a short period of time likewise at 350-580 deg.C to form the AlAs single atom layer by the molecular ray epitaxy method. The film is then subjected to the heat treatment while the irradiation of the As molecular rays at the high temp. of 750-850 deg.C is continued by this single atom layer as a cap layer, by which the GaAs layer having the excellent film quality is formed.

Description

[Detailed Description of the Invention] [Summary] Regarding improvements to a method for manufacturing a gallium arsenide layer on a silicon substrate and a method for manufacturing a gallium arsenide/aluminum gallium arsenide Mi eyebrow body on a silicon substrate. To provide a method for manufacturing a high-quality gallium arsenide layer (first objective), and to provide a method for manufacturing a high-quality gallium arsenide/aluminum gallium arsenide laminate on a silicon substrate (second objective). To achieve the first objective, gallium arsenide N (based on the difference in thermal expansion coefficient It is formed based on stress such as "warp" (crystal defects do not occur), and a monoatomic layer of aluminum arsenic is used as a cap layer, and heat treatment is performed at high temperature while continuing irradiation with arsenic molecular beam.
1196 of the gallium arsenide layer, and to achieve the second objective, a monoatomic layer of aluminum arsenide is formed at a low temperature on the gallium arsenide layer formed on a silicon substrate, and the above-mentioned monoatomic layer is formed at a high temperature. A monoatomic layer of aluminum arsenic is irradiated with an arsenic molecular beam and an aluminum molecular beam for a short time to form a diatomic layer of aluminum arsenic,
The gist of this method is to form an aluminum gallium arsenide layer on this three-atomic layer using molecular beam epitaxial growth at high temperatures.

[Industrial Field of Application] The present invention relates to improvements in a method for manufacturing a gallium arsenide layer on a silicon substrate and a method for manufacturing a gallium arsenide/aluminum gallium arsenide laminate on a silicon substrate.

[Conventional technology]

Gallium arsenide has high carrier mobility, so it is extremely useful as a material for semiconductor devices, etc.
Aluminum gallium arsenide laminates are extremely useful as materials for HEMTs and the like.

In the prior art, these were all formed on a gallium arsenide substrate.

[Problem to be solved by the invention]

However, it was difficult to manufacture large-diameter gallium arsenide substrates, which caused a decrease in throughput.
It has been desired to develop a technology for manufacturing a gallium arsenide layer or an aluminum gallium arsenide laminate on a silicon substrate, which allows easy manufacture of a large-diameter substrate.

However, since silicon and gallium arsenide have different crystallinity, it is difficult to deposit single-crystal gallium arsenide on the silicon substrate unless it is made extremely thin. Even if the difficulties due to the difference in gender are overcome, this case is practically impractical because the silicon substrate is easily damaged during the process.

Therefore, it has been desired to develop a method for manufacturing a high-quality single-crystal gallium arsenide layer on a silicon substrate.

In addition, in order to manufacture HEMTs, etc., a gallium arsenide/aluminum gallium arsenide laminate is required as an intermediate, but n-type impurities contained in the n-type aluminum gallium arsenide layer may diffuse into the gallium arsenide layer. In order to prevent this, an aluminum gallium arsenide layer (intermediate layer) containing no impurities is formed between the n-type aluminum gallium arsenide layer and the gallium arsenide layer at a low temperature range of about 580 to 680°C. The reason we had to use such a low growth temperature is that the underlying gallium arsenide is +1
(This is to avoid being affected by j. I couldn't escape the drawback of not having one.

Therefore, it has been desired to develop a method for manufacturing a high-quality gallium arsenide/aluminum gallium arsenide li layer on a silicon substrate.

Note that when epitaxially growing a single crystal, the higher the reaction temperature, the better the film quality. On the other hand, when growing a single crystal epitaxially on materials with different coefficients of thermal expansion, the lower the reaction temperature, the better the film quality. This is well known.

The purpose of the present invention is to meet these demands; the first purpose is to provide a method for manufacturing a gallium arsenide layer on a silicon substrate, and the second purpose is to provide a method for manufacturing a gallium arsenide layer on a silicon substrate. An object of the present invention is to provide a method for manufacturing a gallium arsenide/aluminum gallium arsenide laminate.

[Means to solve the problem]

The first object of the present invention is to use a molecular beam epitaxial growth method in a temperature range of 350'C to 580°C.
A gallium arsenide layer (2) is formed on a silicon substrate (1), and a monoatomic layer of aluminum arsenide (3 ), and using the aluminum arsenic monoatomic layer (3) as a cap layer, the temperature was 750°C to 85°C.
Arsenic molecular beam irradiation is performed at 1! in the temperature Ff range of 0℃! This is achieved by a method for manufacturing a gallium arsenide layer, which comprises the step of performing a heat treatment to improve the modification of the gallium arsenide layer (2).

A second object of the present invention is to apply gallium arsenide IN (2) formed on a silicon substrate (1) to a temperature of 350°C to 580°C.
aluminum by short-term irradiation with arsenic molecular beams and aluminum molecular beams in the temperature range of .

A monoatomic layer (3) of arsenic is formed, and the monoatomic layer (3) of aluminum arsenic is formed in a temperature range of 750°C to 850°C.
3) is irradiated with an arsenic molecular beam and an aluminum molecular beam for a short time to form a diatomic layer (4) of aluminum arsenic;
Gallium arsenide/aluminum gallium having a step of forming aluminum gallium arsenide Fl (5, 6, 7) on the diatomic N (4) using a molecular beam epitaxial growth method in a temperature range of 750°C to 850°C. arsenic a
This is achieved by a method for manufacturing a layered body.

[Effect]

In the first method, (a) gallium arsenide M2 is formed at a much lower temperature (350°C to 580°C) than in the prior art, based on the difference in thermal expansion between silicon and gallium arsenide. (b) By using a monoatomic layer 3 of aluminum arsenic, which is an insulator but is an extremely thin monoatomic layer and does not substantially increase the electrical resistance, as a cap layer, Much higher temperatures than in the prior art (750°C to 850°C)
(c) Since the heat treatment is carried out with the heat treatment, (c) a sufficiently large heat treatment effect is realized, and gallium arsenide N21 of sufficiently high quality is formed on the silicon substrate 1.

In the second means, (a) in addition to the effect of the first means, (b) a triatomic layer of aluminum arsenic is used as the intermediate layer, so the temperature is high at 750°C to 850°C. In this way, an n-type aluminum gallium arsenide layer can be formed, and (c) the film quality of the gallium arsenide/aluminum gallium arsenide laminate becomes extremely good.

〔Example〕

Hereinafter, a method for manufacturing a gallium arsenide layer on a silicon substrate and a method for manufacturing a gallium arsenide/aluminum gallium arsenide layered body on a silicon substrate according to an embodiment of the present invention will be described below with reference to the drawings.

1st (on silicon, 'J3 1st
Refer to figure a. A gallium arsenide layer 2 with a thickness of 2n is formed on a silicon substrate-1 with a thickness of about 500n using molecular beam epitaxial growth in a temperature range of 350°C to 580°C. Since this growth temperature is low, crystal defects due to stress such as r-warpage do not occur due to the difference in thermal expansion coefficients between silicon and gallium arsenide. It is unavoidable that the film quality is inferior.

Next, in a temperature range of 350°C to 580°C, using the molecular beam epitaxial growth method, arsenic molecular beams and aluminum molecular beams are grown in an extremely short time (6,4XIO
A monoatomic layer 3 of aluminum arsenic is irradiated to a thickness of approximately 2.8 cm.

Refer to Figure 1b.Furthermore, using this aluminum arsenic monoatomic N3 as a cap layer, heat treatment is performed at a high temperature of 750°C to 850°C while irradiating an arsenic molecular beam.This heat treatment temperature is sufficiently high, so that the desired heat treatment can be carried out. The effect was obtained, the film quality of gallium arsenide J112 was improved, and gallium arsenide 11 of sufficiently high quality was obtained.
21 is obtained.

Refer again to FIGS. 1a and 1b. By using the steps described in the first example, as shown in FIGS. and form.

Refer to Figure 1C Next, using the molecular beam epitaxial growth method, arsenic molecular beams and aluminum molecular beams are grown in a temperature range of 750°C to 850°C in an extremely short period of time (1,3
m-'') to form a diatomic layer 4 of aluminum arsenic approximately 5.6 mm thick.

Next, an undoped aluminum gallium arsenide layer 5 (aluminum mixed crystal ratio is 0.15 to 0.3) is heated at about 680°C.
At a reaction temperature of
．． 15 to 0.3, and the impurity concentration is lXl0”c+a
-") to a thickness of approximately 900 ml, and further, n-type aluminum gallium arsenide W16 (aluminum mixed crystal ratio is 0.
15 to 0.3, and the impurity concentration is 1.5XIO"el
It grows to a thickness of about 100 people.

In the aluminum gallium arsenide/gallium arsenide/silicon laminate formed through the above steps, the intermediate M4
-3 fully exhibits its function, and the film quality of aluminum gallium arsenide 5, 6, and 7 is sufficiently good.

〔Effect of the invention〕

As explained above, the method for manufacturing a gallium arsenide layer on a silicon substrate according to the present invention is described below. ! ``Gallium arsenide N (no crystal defects due to stress such as "warp" due to differences in thermal expansion coefficients) is formed on a silicon substrate using molecular beam epitaxial growth at low temperatures, and aluminum arsenide It is said that the film quality of the gallium arsenide layer is extremely good because it is supposed to improve the III￥t of the gallium arsenide layer by using a monoatomic layer as a cap layer and performing heat treatment at high temperature while continuously irradiating the arsenic molecular beam. be.

Further, in the method of manufacturing gallium arsenide/aluminum gallium arsenide 41N on a silicon substrate according to the present invention, in the gallium arsenide layer formed on the silicon substrate,
Forms a monoatomic layer of aluminum arsenic at low temperatures,
At high temperatures, the monoatomic layer of aluminum arsenic
By irradiating arsenic molecular beam and aluminum molecular beam for a short time,
A diatomic layer of aluminum arsenide is formed, and an aluminum gallium arsenide layer is formed on this triatomic layer using molecular beam epitaxial growth at high temperatures. The film quality of both layers is good, and the composition ratio is exactly the desired value even at the boundary between the aluminum gallium arsenide layer and the gallium arsenide layer.

[Brief explanation of the drawing]

FIGS. 1a and 1b are explanatory diagrams of a method for manufacturing a gallium arsenide layer on a silicon substrate according to the present invention. FIG. 1c is an explanatory diagram of a method for manufacturing a gallium arsenide/aluminum gallium arsenide laminate on a silicon substrate according to the present invention. 1... Silicon substrate, 2... Gallium arsenide layer, 21... Good quality gallium arsenide layer, 3... Aluminum arsenide monoatomic layer (cap layer), 4
... Aluminum arsenic diatomic N (middle III), 5.
...Undoped aluminum gallium arsenide layer (intermediate layer), 6,7...n-type aluminum gallium arsenide layer.

Claims (1)

[Claims] [1] A silicon substrate (1) is grown using a molecular beam epitaxial growth method in a temperature range of 350°C to 580°C.
Form a gallium arsenide layer (2) on top and heat at 350°C to 580°C.
A monoatomic layer of aluminum arsenic (
3) is formed, the monoatomic layer of aluminum arsenic (3) is used as a cap layer, and heat treatment is performed in a temperature range of 750 ° C. to 850 ° C. while continuing arsenic molecular beam irradiation,
A method for manufacturing a gallium arsenide layer, comprising the step of improving the film quality of the gallium arsenide layer (2). [2] The gallium arsenide layer (2) formed on the silicon substrate (1) is heated in a temperature range of 350°C to 580°C.
By irradiating arsenic molecular beam and aluminum molecular beam for a short time,
Forming a monoatomic layer (3) of aluminum arsenic, irradiating the monoatomic layer (3) of aluminum arsenic with an arsenic molecular beam and an aluminum molecular beam for a short time in a temperature range of 750°C to 850°C, A diatomic layer (4) of aluminum arsenide is formed, and an aluminum gallium arsenide layer (5, 6, 7) A method for producing a gallium arsenide/aluminum gallium arsenide laminate, comprising the step of forming gallium arsenide/aluminum gallium arsenide.