JPH01155630A - Manufacture of semiconductor device - Google Patents

Abstract

PURPOSE:To form a large GaN film of quality on a silicon substrate at low temperature by vapor phase epitaxy with H2+N2 in an ECR plasma producing chamber and TEG or TMG in a plasma reaction chamber. CONSTITUTION:The surface of (111)4 deg. off or (100)4 deg. off silicon substrate is cleaned up with H2 gas at 800 deg.C using an electron cyclotron resonance(ECR) plasma vapor depositing device. Next, while keeping the temperature of the silicon substrate at 400-500 deg.C, a spontaneous oxide film on the silicon substrate is removed by H2ECR plasma and then H2+N2 is led in the ECR plasma producing chamber 11 at the same temperature while triethylgallium(TEG) or trimethylgallium(TMG) is led in a plasma reaction chamber 12 to epitaxially deposit gallium nitride(GaN) on the silicon substrate. Through these procedures, GaN is vapor-deposited on the silicon substrate at low temperature to form an excellent GaN film in large space.

Description

[Detailed description of the invention] [Summary] Gallium nitride (G
Regarding a method for epitaxially growing GaN on a silicon substrate (silicon wafer), the purpose of this study is to provide a method for forming a large-area, high-quality GaN film on a silicon substrate (silicon wafer) by vapor phase growth at low temperatures. Resonance (EC
R) Using a plasma vapor phase epitaxy device, (111) 4'
Clean the surface of the silicon substrate with Hz gas at 800°C, then keep the silicon substrate temperature at 400-500°C, remove the native oxide film on the silicon substrate with 82ECR plasma, and clean the surface of the silicon substrate with Hz gas at 800°C. Temperature H2+N2 in an ECR plasma generation chamber, triethyl gallium (TEG) or trimethyl gallium (TMG)
) is introduced into a plasma reaction chamber to epitaxially grow gallium nitride (GaN) on a silicon substrate.

[Industrial application field]

The present invention relates to a method for epitaxially growing gallium nitride (GaN) on a silicon substrate at a low temperature of 400-500°C.

[Conventional technology]

Conventionally, green to blue light emitting diodes have been produced using a sapphire substrate with a large bandgap (EG) for visible light.
It has been formed by liquid phase growth of aN. Ga
N has maximum intensity in the blue wavelength of 490 nm, and blue LED
However, vapor phase growth requires high temperatures of over 1000°C.
Since the melting point of silicon is 1360° C., no attempt has been made to deposit GaN on a silicon substrate.

[Problem that the invention seeks to solve]

As mentioned above, an epitaxial layer of GaN can only be obtained at a temperature of 1000°C or higher, and even if it were possible, it would be difficult to obtain a high-quality GaN epitaxial layer over a large area due to the difference in thermal expansion coefficient between the substrate and the epitaxial layer. Currently, GaN is grown on sapphire because GaN cannot be formed on sapphire.
There are expectations for a technology that can vapor phase grow GaN on a silicon substrate with a diameter of m).

Therefore, an object of the present invention is to provide a method for forming a large-area, high-quality GaN film by vapor-phase growing GaN on a silicon substrate (silicon wafer) at a low temperature.

[Failure to solve the problem]

The above problem can be solved by using an electron cyclotron resonance (ECR) plasma vapor phase epitaxy apparatus to grow the surface of a (111) 4° off or (100) 4' off silicon substrate at 800°C.
After cleaning with N2 gas at the same temperature, the silicon substrate temperature was maintained at 400 to 500°C, the natural oxide film on the silicon substrate was removed using H2ECR plasma, and at the same temperature, H,
+NZ to ECR plasma generation chamber, triethyl gallium (
The problem is solved by a semiconductor device manufacturing method characterized in that gallium nitride (GaN) is epitaxially grown on a silicon substrate by introducing TEG or trimethyl gallium (TMG) into a plasma reaction chamber.

[Effect]

In the present invention, the following measures were adopted in order to lower the process temperature and improve the quality of the GaN epitaxial layer.

The crystal lattice mismatch (m
Silicon (111) 4 to prevent is-match)
°OFF GaN is grown on the substrate.

The substrate temperature during growth is 400 to 500° C., and triethyl gallium (TEG) or trimethyl gallium (TMG) and N 2 are used as source gases for growth.

Introducing N2 gas into the plasma generation chamber, ECR plasma N
2 is generated, and TEG or TMG is introduced into the reaction chamber by bubbling with a carrier of N2 or He.

〔Example] Hereinafter, the present invention will be specifically explained with reference to illustrated embodiments.

A divergent magnetic field type ECR-CVD apparatus for carrying out the method of the present invention is comprised of a plasma generation chamber 11 and a plasma reaction chamber 12, as shown in FIG. A microwave with a frequency of 2.45 GHz generated by a microwave oscillator 13 is introduced into the ECR plasma generation chamber 11 through a rectangular waveguide 14 . A magnetic coil 15 is installed around the plasma generation chamber 110.
are arranged to satisfy ECR conditions within the plasma generation chamber 11. In addition, the exhaust configuration is the plasma generation chamber 11
and plasma reaction chamber 12 with a turbomolecular compound pump (T
, M, P) 16 (displacement: 18001 /5ec
), mechanical booster pump (M, B.

p, ) 17 (roots pump) is used to exhaust the air. In FIG. 1, 18 is a plasma shutter, 19 is a sample, 20 is a heater, 21 is a rotary pump (R, P,), and 22 is a matching box.

The process sequence is shown in the diagram of FIG. 2, in which the horizontal axis shows the reaction time in minutes (min) and the vertical axis shows the temperature in [° C.]. The substrate used for growth (sample 19 in Figure 1) is either silicon (111) 4 @OFF or (100) 4 @O
A FF substrate is used to avoid crystal lattice mismatch. The natural oxide film on the silicon substrate surface is removed by wet processing, and then the substrate temperature is raised to 800°C and N2
Clean the silicon substrate surface with gas (10-2
0m1n).

Next, irradiate H2ECR plasma (1-2 m1n),
Next, a TEM or TMG using He or N2 as a carrier is introduced into the plasma reaction chamber 12. The silicon substrate is of the MO heater vacuum confinement radiation heating type) and is 40
Heat to 0~500''C.
The temperature range of 0° C. was confirmed to be optimal through experiments. The reaction time is determined depending on the GaN film to be grown.

Data regarding the photoluminescence of the GaN film formed as described above is as shown in the diagram of FIG. In the figure, the emission intensity of GaN according to the present invention when using a N2 laser (337 nm) is shown in arbitrary units (A, U,), and the horizontal axis shows energy in (eV). As understood from the figure, the GaN film of the present invention exhibited maximum emission intensity near an energy of 3.5 eV.

Since GaN originally has an N-type conductivity type, it cannot be made into a P-type conductivity type. In this way, by using the MIS structure, the driving voltage is 7 to 8 cm, which is higher than other LEDs. Known.

〔Effect of the invention〕

As described above, according to the present invention, G
It has become possible to form aN film and to put it into practical use as a blue light emitting diode, which could not be formed on a silicon substrate in the past.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram of a divergent magnetic field type ECR plasma device used to carry out the method of the present invention, Fig. 2 is a diagram of the process sequence of the present invention, and Fig. 3 shows the emission intensity of GaN according to the present invention. This is a diagram. In Fig. 1, 11 is a plasma generation chamber, 12 is a plasma reaction chamber, 13 is a microwave oscillator, 14 is a rectangular waveguide, 15 is a magnetic coil, 16 is T, M, P, and 17 is! 1. B, P, 18 is a plasma shutter, 19 is a sample, 20 is a heater, 21 is R, P, 22 is a matching box. Figure 1

Claims (1)

[Claims] Using an electron cyclotron resonance (ECR) plasma vapor phase growth apparatus, the surface of a (111) 4° off or (100) 4° off silicon substrate (19) is cleaned with H_2 gas at 800°C. , Next, the silicon substrate temperature was kept at 400 to 500°C, and H
_2 The natural oxide film on the silicon substrate is removed using ECR plasma, and at the same temperature, H_2 + N_2 is introduced into the ECR plasma generation chamber and triethyl gallium (TEG) or trimethyl gallium (TMG) is introduced into the plasma reaction chamber (12) to form a layer on the silicon substrate. Gallium nitride (GaN)
A method for manufacturing a semiconductor device, comprising epitaxially growing a semiconductor device.