JPH01188678A - Plasma vapor growth apparatus - Google Patents

Abstract

PURPOSE:To reduce dusting in a vacuum tank and to improve cleanliness in the tank by constituting all the surfaces, except those of the materials to be coated, among the surfaces on which solid material is to be deposited of an insulating material. CONSTITUTION:A ceramic coating 11 is applied by the use of ceramic, such as alumina, to all the surfaces, except those of substrates 9, among the surfaces on which solid material is to be deposited, that is, the surface of a high-frequency electrode 2, the surface of a susceptor 3, and the inner surface of a vacuum tank 1. Owing to the above constitution, although films are formed even on the surface of the electrode 2, the surface of the susceptor 3, and the inner surface of the tank 1 mentioned above at the time of depositing a solid material from a vapor phase by means of plasma formation, no peeling occurs to the films at the time of cooling and, as a result, dusting in the tank 1 can be prevented because the wall surfaces are coated with ceramic having thermal expansion coefficient practically equal to that of the wall surfaces.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a plasma vapor phase epitaxy apparatus in which all surfaces on which solids are deposited, excluding deposits, are made of an insulator.

[Conventional technology]

FIG. 2 is a schematic diagram of a capacitively coupled plasma vapor phase growth apparatus described in, for example, "Pacific Semiconductor Plasma Process Technology" Sangyo Tosho (1981), page 181. High frequency electrode (2), susceptor (3),
It consists of a high frequency power source (4), a heater (5), a rotating shaft (6), and a magnetic rotation mechanism.

Next, the operation will be explained. A reaction gas necessary for film formation is introduced into the vacuum chamber (1) through the gas inlet (7), and a high frequency plasma is generated between the high frequency electrode (2) and the susceptor (3) using the high frequency power source (4). Film formation is performed while heating the substrate (9) placed on the susceptor (3) with a heater (5). Further, in order to form a uniform film, the susceptor (3) is rotated by the magnetic rotation mechanism 00 and the rotating shaft (6) during film formation.

[Problem to be solved by the invention]

Conventional plasma vapor phase growth equipment is configured as described above, but during film formation, the spread of high-frequency plasma and the flow and diffusion of active species cause the film to form on the susceptor, the high-frequency electrode surface, and the inner wall of the vacuum chamber in addition to the substrate surface. Form. However, in conventional plasma vapor phase epitaxy equipment, the above-mentioned surfaces and walls are made of metal (mainly stainless steel), and due to the difference in thermal expansion coefficient from the formed film, there is There was a problem in that the membrane peeled off and dust was generated, which deteriorated the cleanliness inside the vacuum chamber.

This invention was made to solve the above-mentioned problems, and can prevent the film from peeling off from the high frequency electrode, the susceptor surface, and the inner wall surface of the vacuum chamber, and can also reduce dust generation inside the vacuum chamber. The purpose of this study is to obtain a plasma vapor phase epitaxy device that enables this.

[Means to solve the problem]

In the plasma vapor phase growth apparatus according to the present invention, all surfaces on which solids are deposited, excluding deposits, are made of an insulator.

[Function] The high frequency electrode of the plasma vapor phase growth apparatus according to the present invention,
The susceptor surface and the vacuum chamber wall are made of an insulating material such as ceramic such as alumina or zirconia or quartz, which has almost the same coefficient of thermal expansion as the film formed on the surface other than the substrate surface due to the spread of high-frequency plasma and the flow and diffusion of active species during film formation. This prevents the film from peeling off from the high frequency electrode, susceptor surface, and vacuum chamber wall surface due to differences in thermal expansion coefficients during cooling.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. 1st
The figure shows the structure of a plasma vapor phase growth apparatus according to an embodiment of the present invention. The difference from the conventional device is the ceramic coat α→ shown in black. In this example, alumina ceramic was used to provide the ceramic coat.

With the structure shown in the above embodiment (Fig. 1), silane gas, oxygen, ammonia gas, nitrogen, hydrogen, etc. are introduced into the vacuum chamber, and a high frequency voltage is applied to form plasma to form an insulating film and a passivation film. Formation of

In this case, due to the spread of the high-frequency plasma and the flow and diffusion of active species, a film is also formed on the high-frequency electrode, the susceptor surface, and the inner wall surface of the vacuum chamber. However, since the wall surface is covered with alumina ceramic, which has almost the same coefficient of thermal expansion,
The film does not peel off during cooling, preventing dust generation inside the vacuum chamber.

Although the above embodiment describes the case where an insulating film and a passivation film are formed, it is also possible to etch an insulating film, and particles newly generated by the etching process can be used to form a high-frequency electrode, a susceptor, and the inner wall surface of a vacuum chamber. A similar effect can be obtained for films formed in the same manner.

〔Effect of the invention〕

As described above, according to the present invention, the high-frequency electrode, the susceptor surface, and the vacuum chamber inner wall surface are made of ceramic such as alumina or zirconia, or quartz, thereby reducing the generation of dust in the vacuum chamber. A vapor phase growth apparatus can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a plasma vapor phase growth apparatus according to an embodiment of the present invention, and FIG. 2 is a block diagram of a conventional plasma application apparatus. (1) is a vacuum chamber, (2) is a high frequency electrode, (3)
is a susceptor, (4) is a high frequency electrode, (5) is a heater,
(6) is a rotating shaft, (7) is a gas inlet, (8) is an exhaust port, (9) is a substrate, the frame is a magnetic rotation mechanism, and (b) is a ceramic coat. In addition, in the figures, the same reference numerals indicate the same or equivalent parts.

Claims (2)

[Claims] (1) A plasma vapor phase epitaxy apparatus for depositing solids from a gas phase, characterized in that all surfaces on which solids are deposited, excluding deposits, are made of an insulator. (2) An insulating film and a passivation film are formed by subjecting silane gas, oxygen, nitrogen, ammonia gas, and hydrogen to plasma decomposition and solid precipitation from a gas phase to form an insulating film and a passivation film. plasma vapor phase growth equipment.