JPH05148655A - Thin film forming apparatus - Google Patents

Abstract

PURPOSE:To form a thin film of good quality at a relatively low temp. by impressing voltage on a substrate holder, feeding a reactive gas to the surface of a substrate and irradiating the surface of the substrate with a free radical. CONSTITUTION:A substrate 3 is held in a vacuum tank 1 by a substrate holder 2. An electrode 4 is arranged in the vicinity of the substrate holder 2. DC voltage is applied through the substrate holder 2 by the electrode 4. A reactive gas is fed to the surface of the substrate 3 from gas introducing tubes 15 and 16. The surface of the substrate 3 is irradiated with one or >= two kinds of free radicals by at least one of free radical beam generators 6 and 8. In this way, the objective thin film forming apparatus applicable also to a semiconductor film or the like can be provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thin film forming apparatus for forming a good quality thin film.

[0002]

2. Description of the Related Art Conventionally, a plasma CVD method for decomposing a gas by DC plasma to deposit a film is already well known.

[0003]

Generally, when a film is formed by a DC plasma CVD apparatus, a DC voltage is applied between the electrode and the substrate to decompose the gas to synthesize the film. However, in the above method, it is difficult to control the composition because the decomposition rate, the activation rate and the ionization rate of the gas are relatively low and the production rate of the reaction product is not so high. An object of the present invention is to accelerate activation of a gas or a reactant by irradiating a substrate with a radical from above in a thin film formation by a DC plasma CVD apparatus, and to form a high-speed thin film while forming a high quality thin film To provide a device.

[0004]

In order to achieve the above object, the present invention provides a substrate holder for holding a substrate in a vacuum chamber, and a DC voltage between the substrate holders arranged in the vicinity of the substrate holder. An electrode to be applied, a gas introduction tube for supplying a reaction gas onto the substrate, and at least one radical beam for irradiating the substrate with one or more radicals.
And a film generator to form a thin film forming apparatus.

[0005]

The reaction product by the DC plasma is further activated by irradiating the substrate with radicals generated from one or more radical beam generators arranged above the substrate. Therefore, a thin film can be formed with good quality and at high speed.

[0006]

EXAMPLES Examples of the present invention will be described below. FIG. 1 is a sectional view showing the overall structure of an embodiment of the present invention.
Substrate holder 2 with heating heater inside vacuum chamber 1
Is provided and the substrate 3 is supported. The heating heater is connected to the heater power source 12. An electrode 4 to which a gas introduction pipe 14 is connected is provided near the substrate holder 2, and the substrate 3 and the electrode 4 are connected by a DC power supply 13. Further, a radical beam generator (A) 6 and a radical beam generator (B) 8 are installed above the substrate 3. Reference numerals 5 and 7 are shutters, 9 and 10 and 11 are valves, and 15 and 16 are gas introduction pipes.

Next, the formation of a diamond thin film by this apparatus will be specifically described. First, the inside of the vacuum chamber 1 is evacuated to 1 × 10 ⁻⁷ Torr or less using a diffusion pump or a turbo pump and an oil rotary pump (neither is shown). The substrate 3 is heated to about 500 ° C., then valves 9 and 10 are opened to introduce gas, and hydrogen and oxygen are introduced respectively. Further, the valve 11 is opened to introduce methanol (or methane) + hydrogen gas (carrier gas) into the vacuum chamber 1. In this state, the electrode 4 and the substrate holder 2 (substrate 3)
A DC voltage is applied between them to generate plasma. Furthermore,
At the same time, the power sources of the radical beam generators (A) and (B) are set to predetermined conditions to grow a film while irradiating hydrogen radicals and oxygen radicals directly on the substrate.

In this embodiment, in this state, a film was formed on the silicon substrate for about 10 minutes. The diamond film thus formed had a thickness of about 1 μm. The formed film was measured by Raman spectroscopy, which was 1330 cm.
Only ^-1 gave a sharp peak. When the Vickers hardness of this film was measured, a value of about 12000 was obtained. This value is the same as natural diamond. Also, when the thermal conductivity of the film was measured, it was about 200 W / K.
A value of cm was obtained. This is the same value as high-pressure synthesized diamond. As described above, it is understood that the present embodiment can obtain a good quality diamond thin film at a relatively low temperature. In this embodiment, the radical beam generator is 2
Although one piece is used, the number is not particularly limited, and one piece or a plurality of pieces may be appropriately selected and used according to the thin film to be formed.

[0009]

As described above, according to the present invention, D
The combination of the reaction product of C plasma and the irradiation of the radical beam from above onto the substrate enhances the activation of the reaction product and can form a good quality thin film at a relatively low temperature. It is also applicable to semiconductor films. A possible thin film forming apparatus can be provided.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an overall structure of a thin film forming apparatus according to an embodiment of the present invention.

[Explanation of symbols]

1 Vacuum Tank 2 Substrate Holder 3 Substrate 4 Electrodes 5,7 Shutter 6,8 Radical Beam Generator 9,10,11 Valve 12 Heater Power Supply 13 DC Power Supply 14,15,1
6 gas introduction pipes

Claims (1)

[Claims] 1. A substrate holder for holding a substrate in a vacuum chamber, an electrode arranged near the substrate holder for applying a DC voltage between the substrate holders, and a gas for supplying a reaction gas onto the substrate. A thin film forming apparatus comprising: an introduction tube; and at least one radical beam generator for irradiating the substrate with one or more radicals.