JPH06232043A - Plasma device - Google Patents

Abstract

PURPOSE:To secure a film which is stable and uniform for a long time by preventing the contamination of the internal surface of the discharge chamber of a plasma device which is used for forming a thin film on a substrate by utilizing a vacuum and, at the same time, to improve the working efficiency of the plasma device by simplifying the cleaning, etc., of the internal surface of the discharge chamber. CONSTITUTION:The wall of the discharge chamber of the device is constructed in a double-wall structure composed of an airtight outside wall 2, porous inside wall 3 with fine holes, and a space between the walls 2 and 3. Therefore, since an inert gas 9 can be supplied into the chamber from the entire surface of the wall 3 and the deposition of monomer gas 10 plasma on the internal surface of the wall 3 can be prevented, a film which is stable and uniform for a long time can be obtained and, at the same time, since the contamination of the internal surface of the discharge chamber can be prevented, the cleaning work of the discharge chamber can be simplified and the working efficiency of the plasma device can be improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma device for forming a thin film on a substrate in vacuum, and more particularly to a plasma device having excellent thin film performance and work efficiency.

[0002]

2. Description of the Related Art In recent years, plasma devices utilizing vacuum have been widely used in the fields of semiconductors and recording media for the purpose of high integration and high density. In general, these devices have a discharge chamber and a substrate (which may be attached to a substrate holder and fixed or moved by the action of a substrate transfer system) in a vacuum chamber, and thereby plasma is generated. The material is attached to the surface of the substrate and used for thin film formation and protective film formation.

A conventional plasma device will be described below. FIG. 4 is a sectional view showing the outline of a conventional plasma device. In FIG. 4, 1 is a vacuum chamber, 11 is a discharge chamber, 4 is a cathode (cathode) which also serves as a substrate holder, 5 is a substrate, 6
Is a vacuum pump, 7 is a DC power source, 8 is a mesh anode (anode), 9 is an inert gas, and 10 is a monomer gas.

The operation of the plasma device configured as described above will be described below. First, the substrate 5 is attached to the anode 4 serving as the substrate holder, and the vacuum chamber 1 and the discharge chamber 11 are evacuated by the vacuum pump 6 to about 10 ⁻⁵ torr. When the inert gas 9 and the monomer gas 10 are supplied to the discharge chamber 11 and a voltage is applied to the mesh-shaped cathode 8 by the DC power supply 7 to bring the inert gas 9 and the monomer gas 10 into a plasma state, the monomer gas 10 is deposited on the substrate. Deposited as a polymerized film on.

[0005]

However, in the above-mentioned conventional structure, the monomer gas 10 in the plasma state is not only deposited on the substrate 4 but also on the inside of the discharge chamber 11, so that the discharge is continued for a long time. Then, there is a problem that the thickness of the film deposited inside the discharge chamber 11 increases, and the peeled film adheres to the substrate to form a non-uniform film.

The present invention solves the above-mentioned problems of the prior art by providing a stable and uniform film for a long time, and preventing contamination inside the discharge chamber 11 to simplify cleaning inside the discharge chamber 11 and the like. It aims to provide improved work efficiency.

[0007]

In order to achieve this object, the plasma device of the present invention has a double wall structure in which the discharge chamber wall has an outer wall having airtightness and a porous inner wall having fine holes. have.

[0008]

With this configuration, first, the inert gas is supplied to the space between the outer wall of the discharge chamber and the inner wall of the discharge chamber, and the inert gas is supplied into the inner wall of the discharge chamber, that is, the discharge chamber through the fine holes in the inner wall of the discharge chamber. It The monomer gas is directly supplied into the inner wall of the discharge chamber. When a voltage is applied and the inert gas and the monomer gas are in a plasma state, the inside of the discharge chamber inner wall is covered with the inert gas, so that the accumulation of the monomer gas plasma inside the discharge chamber inner wall can be prevented.

[0009]

【Example】

(Embodiment 1) An embodiment of the present invention will be described below with reference to the drawings by taking a case of a plasma CVD method as an example.

FIG. 1 is a sectional view of an embodiment of the present invention.
Is the outer wall of the discharge chamber, and 3 is the inner wall of the discharge chamber.

First, a silicon wafer is attached to the cathode 4 serving as a substrate holder, and a vacuum pump 6 (rotary pump,
Evacuate to about 10 ^-5 torr with a turbo molecular pump. Next, argon gas is supplied as the inert gas 9 so that the degree of vacuum in the discharge chamber is 0.05 torr. When the degree of vacuum inside is stable and the supply amount of argon gas is determined, the supply is stopped, and then the supply amount of methane gas as the monomer gas 10 is adjusted so that the degree of vacuum in the discharge chamber becomes 0.1 torr. When the supply amount of methane gas is determined, argon gas is supplied in the determined supply amount and waits for about 5 minutes until the degree of vacuum in the discharge chamber stabilizes. When a voltage of 800 V is applied to the mesh-shaped anode 8 by the DC power source 7 after the degree of vacuum is stabilized, the argon gas and the methane gas are in a plasma state, and the methane gas becomes diamond-like carbon (DLC) and is deposited on the silicon wafer. When plasma CVD processing was performed in the conventional configuration, peeling was confirmed in the discharge chamber after 6 hours had elapsed, and after 10 hours, the silicon wafer was chipped off, but in the example of the present invention, after 15 hours had elapsed, the discharge chamber remained. There was no peeling from.

(Second Embodiment) A second embodiment of the present invention will be described with reference to FIG. Here, the configuration is the same as that of the first embodiment except that argon gas is supplied to the inner wall and methane gas is supplied to the space between the outer wall and the inner wall. As a result of the same experiment as in Example 1, the same effect as in Example 1 was obtained.

(Embodiment 3) A third embodiment of the present invention will be described with reference to FIG. Here, argon gas and methane gas are supplied to the space between the outer wall and the inner wall. As a result of the same experiment as in Example 1, the same effect as in Example 1 was obtained.

[0014]

As described above, according to the present invention, the discharge chamber wall has a double wall structure of an outer wall having airtightness and a porous inner wall having fine holes, and a space is provided between the outer wall and the inner wall. Since it is possible to supply an inert gas from the entire inner wall and to prevent the monomer gas plasma from being deposited on the inner side of the inner wall of the discharge chamber, it is possible to provide a stable and uniform film for a long time, It is possible to realize an excellent plasma device capable of improving work efficiency by simplifying cleaning of the discharge chamber and the like by preventing indoor pollution.

[Brief description of drawings]

FIG. 1 is a sectional view of a plasma device used in a first embodiment of the present invention.

FIG. 2 is a sectional view of a plasma device used in a second embodiment of the present invention.

FIG. 3 is a sectional view of a plasma device used in a third embodiment of the present invention.

FIG. 4 is a sectional view of a conventional plasma device.

[Explanation of symbols]

 1 vacuum chamber 2 outer wall of discharge chamber 3 inner wall of discharge chamber 4 cathode serving as substrate holder 5 substrate 6 vacuum pump 7 DC power supply 8 mesh-shaped anode 9 inert gas 10 monomer gas 11 discharge chamber

Claims (4)

[Claims] 1. A plasma device having a discharge chamber for forming a thin film on a substrate in a vacuum, wherein the discharge chamber wall has a double wall structure of an outer wall having airtightness and a porous inner wall having fine holes. A plasma device having a space between the outer wall and the inner wall. 2. The plasma apparatus according to claim 1, further comprising a mechanism for supplying the monomer gas inside the inner wall and supplying the inert gas into the space between the outer wall and the inner wall. 3. The plasma apparatus according to claim 1, further comprising a mechanism for supplying the inert gas inside the inner wall and supplying the monomer gas into the space between the outer wall and the inner wall. 4. The plasma apparatus according to claim 1, further comprising a mechanism for supplying the inert gas and the monomer gas to the space between the outer wall and the inner wall.