JPS63213656A - Device for forming thin carbon film - Google Patents

Abstract

PURPOSE:To form a homogeneous and dense thin carbon film on a substrate at a high rate, by halving a reaction chamber with a plate electrode having a circulating hole, and activating the graphite powder from a graphite target with hydrogen plasma at the time of forming a thin carbon film on the substrate by a reactive sputtering method. CONSTITUTION:The inside of a vacuum chamber 2 is separated by the plate electrode 16 having a circulating port 16a into an A section and a B section. The inside of the A section is evacuated from an exhaust hole 4, and Ar as an inert gas is then introduced from an inlet 3. Meanwhile, a high-frequency voltage is impressed between a target holder 5 and a counter electrode 11, and the graphite target 6 is decomposed and scattered by the plasma of gaseous Ar. Gaseous H2 is simultaneously introduced into the B section from an inlet 20 to produce hydrogen plasma by a high-frequency voltage between the plate electrode 16 and a substrate holder 12, the scattered graphite particles enter the B section from the circulating port 16a and are activated by the hydrogen plasma, the activated particles are uniformly, densely, and firmly adhered onto a substrate 13, and a hard thin carbon film is formed at a high rate.

Description

DETAILED DESCRIPTION OF THE INVENTION A. Industrial Application Field The present invention relates to an apparatus for forming a carbon thin film on a substrate by reactive sputtering, and in particular, after sputtering graphite with an inert gas, graphite particles are sputtered with hydrogen plasma. The present invention relates to an apparatus for forming a carbon thin film that is decomposed and formed using a carbon film.

B0 Summary of the Invention The present invention provides a magnetron-type target holder that holds a target facing each other in a vacuum chamber and a counter electrode, and also provides a substrate holder that holds a substrate above the counter electrode. - In an apparatus for forming a carbon thin film on a substrate placed on a substrate holder by applying a high frequency voltage between a get holder and a counter electrode.

The vacuum chamber is partitioned by a plate-shaped electrode having a flow hole to provide a first section and a second section, the target holder and the counter electrode are arranged in the first section, and an inert gas can be introduced into the second section. By arranging the substrate holder in the chamber and applying a high frequency voltage between the substrate holder and the plate electrode, and making it possible to introduce H2 gas into the second section, an inert gas is introduced into the first section. The primary generated species generated by sputtering in the atmosphere are decomposed by hydrogen plasma to create active species, making it possible to form a dense thin film containing no excess hydrogen on the substrate at high speed. It is something.

C5 Prior Art A conventional carbon thin film forming apparatus is shown in FIG. In the figure, reference numeral 2 denotes a metal container, which has a gas inlet 3 on its side, a vacuum suction port 4 on its bottom, and a vacuum chamber 1 formed inside the container. The gas inlet 3 is
It is connected to an external hydrogen gas tank 14 via a mass flow controller 15 by an air supply pipe. A magnetron-type target holder electrode 5 equipped with an electromagnet 9 is provided approximately in the center of the vacuum chamber 1, and a disk-shaped graphite target 6 is held on top of the magnetron-type target holder electrode 5.

The target holder electrode 5 is connected to an external high frequency power source 7 via a matching box 8.

10 is an insulating member. A circular counter electrode 11 is installed above the graphite target 6 and concentrically opposed to the graphite target 6, and a high frequency voltage is applied between the two. Above the counter electrode 11 is a substrate holder 1.
2 is installed, and a substrate 1 on which a carbon thin film is to be formed on the lower surface.
3 is installed.

When forming a carbon thin film on the substrate 13 using this apparatus, a high frequency voltage is applied between the target holder electrode 5 and the opposing pole 11 while the vacuum chamber 1 is set to a low pressure hydrogen gas atmosphere. In this case, the graphite target 6 as a carbon source on the target holder electrode 5 evaporates, is diffused by the action of hydrogen plasma, and adheres to the substrate 13.
Form a carbon thin film.

D0 Problems to be Solved by the Invention In the conventional carbon thin film forming apparatus described above, the film formation rate is about 1/1 degree slower than that of the general sputtering method, and the sputtering is performed in a hydrogen gas atmosphere, making it difficult to activate the film. The reaction with hydrogen is promoted and hydrogen is contained excessively in the film, and as a result m
The film becomes a soft film with a hardness of 2 to 3, and since the reaction in hydrogen plasma is repeated, complex generated species are incorporated into the film, forming an unstable and inhomogeneous thin film. There is a problem with this.

Therefore, the present invention aims to solve the above-mentioned problems and provide an apparatus capable of increasing the film formation rate, eliminating excess hydrogen content, and forming a homogeneous and dense carbon thin film.

Means for Solving the E0 Problem In the carbon thin film forming apparatus of the present invention, an inert gas atmosphere is provided in the first section of the vacuum chamber partitioned by plate-shaped electrodes, and a high frequency wave is applied between the graphite target and the counter electrode. A voltage is applied to generate an inert gas plasma, which evaporates the graphite relatively coarsely and scatters the large-grained primary generated species. This primary generated species is then introduced into the second compartment, which has a hydrogen gas atmosphere. Here, a high frequency voltage is applied between the plate electrode and the substrate holder to generate hydrogen plasma, and the primary generated species are exposed to the plasma to react with H2, thereby forming a carbon thin film on the substrate. At this time, since the inert gas has a larger mass than the hydrogen gas, a large amount of primary generated species with large particles is generated. Further, by exposure to hydrogen plasma, the primary generated species are decomposed and activated, forming a dense and strong thin film at high speed. Hydrogen contained in the film is reduced by the two-step sputtering as described above.

G. Embodiment An embodiment of the present invention is shown in FIGS. 1 to 3. FIG. 1 is a schematic longitudinal sectional front view of a carbon thin film forming apparatus, FIG. 2 is a plan view of a plate-shaped electrode, and FIG. 3 is a graph showing an infrared absorption spectrum of the formed carbon thin film. Note that the same components as those of the conventional device in FIG. 1 and FIG.

In FIG. 1, a vacuum chamber 1 is formed by a plate electrode 16 provided above a counter electrode 11. It is divided into second compartments A and B. The plate-shaped electrode 16 includes a hole 16a that communicates between the first and second sections A and B, and is connected to a high-frequency power source 18 via an external matching box 17. This plate-shaped electrode 16 is attached to the inside of the container 2 via an insulating member 19. The gas inlet 3 of the first section A communicates with an external Ar gas tank 22. On the other hand, in the second section B, a gas inlet 20 is opened and communicated with the hydrogen gas tank 14 via a mass flow controller 2 via an air pipe.

Next, the operation of the above embodiment will be explained. First, the inside of the vacuum chamber 1 is evacuated, the mass flow controllers 15 and 21 are adjusted, and Ar gas is introduced into the first section A side and hydrogen gas is introduced into the second section B side. As a result, the inside of the vacuum chamber 1 becomes a pseudo two-phase system with upper and lower atmospheres different from each other. Each section A,
After the inside of B reaches a predetermined pressure, a high frequency voltage is applied between the target holder electrode 5 and the counter electrode 11 to decompose and scatter the graphite target 6. The decomposed graphite target particles have a mass of Ar gas. Since it is larger than that of hydrogen gas, it is relatively large. The large size of these particles contributes to high speed film formation.

Next, a high frequency voltage is applied between the plate electrode 16 and the substrate holder 12 to generate hydrogen plasma.

Then, the scattered graphite particles pass through the communication holes 16a of the plate-shaped electrode 16 and enter the second section B, where they are exposed to hydrogen plasma. Then, it is decomposed by hydrogen plasma, reacts with H2, is activated, and adheres densely and firmly onto the substrate 13. In this way, a uniform, hard (MOHS hardness 6-8) thin film is formed.

The infrared absorption spectrum of the carbon thin film formed as described above is compared with that of the carbon thin film formed by the conventional apparatus shown in FIG. 4, as shown in FIG. From this result, it is clear that the excess hydrogen contained in the formed carbon thin film was reduced.

H1 Effects of the Invention As described above, the present invention provides a magnetron-type target holder that holds a target facing each other in a vacuum chamber and a counter electrode, and also provides a substrate holder that holds a substrate above the counter electrode. In an apparatus for forming a carbon thin film on a substrate placed on a substrate holder by applying a high frequency voltage between a target holder and a counter electrode in a gas atmosphere, the vacuum chamber is partitioned by a plate-shaped electrode having a flow hole to form a first section. A second compartment is provided, the target holder and the counter electrode are arranged in the first compartment and an inert gas can be introduced, the substrate holder is arranged in the second compartment, and the substrate holder and the plate electrode are arranged. Since a high frequency voltage is applied between the two sections and hydrogen gas can be introduced into the second section, the following effects are achieved.

(1) A hard and uniform carbon thin film can be formed in a short time with less excess hydrogen content.

(2) Since the local plasma activity (non-equilibrium degree) increases, a denser and more stable film can be formed.

(3) Film thickness distribution can be moderately suppressed.

(4) Since the device has a simple structure, it is easy to use and easy to maintain and inspect.

[Brief explanation of the drawing]

FIG. 1 is a schematic longitudinal sectional front view of the carbon thin film forming apparatus of the present invention, FIG. 2 is a plan view of a plate-shaped electrode, FIG. 3 is a graph showing the infrared absorption spectrum of the formed carbon thin film, and FIG. The figure is a schematic longitudinal sectional front view of a conventional device. DESCRIPTION OF SYMBOLS 1... Vacuum chamber, 2... Gas inlet, 5... Plate electrode, 6... Graphite target, 11... Counter electrode, 12... Substrate holder, 13... Substrate, 14・
...Hydrogen gas tank, 15...Mass flow controller, 16...Plate M pole, 20...Gas inlet, 21
... mass flow controller, 22 ... inert gas (Ar gas) tank, A ... first section, B ... second
section. Figure T
ξ (da (cryi')

Claims (1)

[Claims] A magnetron-type target holder that holds targets facing each other in a vacuum chamber and a counter electrode are provided, and a substrate holder that holds a substrate is provided above the counter electrode.
In an apparatus for forming a carbon thin film on a substrate placed on a substrate holder by applying a high frequency voltage between a target holder and a counter electrode in a two-gas atmosphere, the vacuum chamber is partitioned by a plate-shaped electrode having a flow hole, and a first A section and a second section are provided, and the first
The target holder and the counter electrode are arranged in the compartment, and an inert gas can be introduced into the compartment, the substrate holder is arranged in the second compartment, and a high frequency voltage is applied between the substrate holder and the plate-shaped electrode. Also, H_2 in the second section
A carbon thin film forming apparatus characterized in that a gas can be introduced.