JPH09235113A - Evaporator for high-melting substance - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an evaporator for a high-melting substance designed to readily provide a vapor of the high-melting substance in a large amount in a state of a secured strength of the substance to be an object of evaporation. SOLUTION: This evaporator for a high-melting substance is obtained by arranging plural magnets 12, different in magnetic poles and alternately adjacent in a state thereof surrounding a high-frequency electrode 2 between the high-frequency electrode 2 to be evaporated and a vacuum chamber 1. The evaporator is capable of causing the discharge across the vacuum chamber 1 and the high- frequency electrode 2 with a high-frequency power source 3, generating a plasma, electrically floating the high-frequency electrode 2 from an earth with a blocking capacitor 8, thereby providing the high-frequency electrode 2 with a negative potential with reference to the plasma potential in a DC system, accelerating positive ions in the plasma in the direction of the high-frequency electrode 2 according to the applied negative potential, making the positive ions collide therewith, heating the high-melting metal constituting the electrode 2 and evaporating the high-melting metal. The evaporated metal is taken out of a takeout port 13 and deposited on a film substrate.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for heating and evaporating a high melting point substance.

[0002]

2. Description of the Prior Art FIG. 4 shows a conventional refractory metal evaporator. As shown in the figure, in this apparatus, an electric current is applied to a fine wire 15 made of a high melting point metal in the vacuum chamber 1 by using a direct current source 16, and the fine wire is heated and vaporized by Joule heat generation.

In this conventional vaporizer for refractory metals, a large current density is required because Joule heating is used for heating. As a result, the wire diameter of the metal to be vaporized needs to be on the order of sub-millimeters, so the wire is easily broken in terms of strength, and the total vapor amount obtained is small.

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a refractory substance vaporizer in which a large amount of vapor of a refractory substance can be easily obtained while sufficiently securing the strength of the substance to be vaporized. It is an issue.

[0005]

In order to solve the above-mentioned problems, in the present invention, a rod-shaped high-frequency electrode made of a high melting point substance to be vaporized is arranged inside the vacuum chamber as a discharge space to form a discharge space. The outer peripheral wall is used as a ground electrode to generate a discharge between the high frequency electrode. In the space between the vacuum chamber and the high frequency electrode, a structure is adopted in which magnets having different magnetic poles are alternately and adjacently arranged so as to surround the high frequency electrode.

In the high-melting-point substance vaporization apparatus of the present invention having the above-described structure, the discharge space is set in the vacuum chamber, and the rod-shaped high-frequency electrode made of the high-melting point substance to be vaporized is placed in the vacuum chamber to form a vacuum. Plasma is generated by generating discharge using the outer peripheral wall of the chamber as a ground electrode.

By the self-biasing action of the non-linear current-voltage characteristic of plasma on the refractory material electrode,
When a negative voltage is applied to the plasma potential by using an external DC power supply, positive ions in the plasma are accelerated toward the refractory material electrode and collide. The energy given to the electrode by the positive ions at the time of this collision can heat and evaporate the refractory substance electrode.

If the distance between the discharge electrodes is made sufficiently large, the state of the generated plasma does not depend on the diameter of the refractory substance electrode, and therefore the refractory substance electrode diameter can be increased, which is sufficient for the refractory substance electrode. While ensuring sufficient strength, a large discharge volume and a large evaporation area are achieved.

Further, by arranging magnets having different magnetic poles alternately adjacent to each other in the vicinity of the outer peripheral wall of the vacuum chamber which is the earth electrode, a magnetic field parallel to the wall surface of the vacuum chamber is formed. This magnetic field is strong only near the walls of the vacuum chamber and charged particles are reflected near the walls.

Therefore, the number of charged particles extinguished on the wall surface can be reduced, and the plasma generation efficiency with respect to the supplied discharge power can be improved. As a result, the evaporation efficiency of the high melting point substance with respect to the supplied discharge power is increased. You can

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION A device according to the present invention will be described below with reference to FIGS.
A specific description will be given based on the embodiment shown in FIG. A rod-shaped electrode 2 (diameter φ2 to 3 mm) made of a high melting point substance (carbon or tungsten) is arranged in the center of a vacuum chamber 1 which serves as a cylindrical (inner diameter of about 40 mm) ground electrode, and a high frequency power source (for example, frequency 13. cause discharge between two electrodes using 56MH _Z) 3, to generate a plasma 4.

The discharge chamber 6 is evacuated in advance by the vacuum pump 5.
The gas to be converted into plasma is supplied from the gas cylinder 7 into the vacuum chamber 1. The refractory metal electrode 2 is made to have a DC negative potential with respect to the plasma potential by electrically floating from the ground using the blocking capacitor 8.
This negative potential is induced by the self-bias action due to the non-linear current-voltage characteristic of plasma, but can also be applied by the external DC voltage source 9.

According to the applied negative potential, the positive ions 10 in the plasma 4 are accelerated toward the refractory electrode 2 and collide with each other. It is heated and evaporated. Therefore, the evaporation amount is controlled by the external DC voltage source 9.

Here, the refractory metal 2 is introduced in the axial direction by the linear motion device 11 in accordance with the consumption of the electrode due to the evaporation of the metal. Magnets 12 having different magnetic poles are arranged in the vicinity of the outer peripheral wall 1 which is a ground electrode, and plays a role of enhancing plasma generation efficiency, that is, evaporation efficiency. A vapor outlet 13 is provided between the magnets, and is used for vapor deposition on the film substrate 14, for example.

The present invention has been specifically described above based on the illustrated embodiments, but the present invention is not limited to these embodiments and within the scope of the present invention shown in the claims. It goes without saying that various changes may be made to the shape and structure.

For example, in the above embodiment, an apparatus for simply vaporizing a refractory metal was shown, but not only simple vaporization but also vaporization with reactivity is possible. For example, when carbon is used as the rod-shaped electrode 2, fullerenes (C ₆₀ , C
₇₀ ) It is possible to use the device for manufacturing.

[0017]

As described in detail above, according to the present invention, there is provided an apparatus capable of sufficiently securing the strength of a metal to be evaporated and easily obtaining a large amount of refractory metal vapor. To be done.

[Brief description of drawings]

FIG. 1 is a perspective view showing a configuration of a high melting point substance evaporation device according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along the line AA of FIG. 1;

FIG. 3 is a sectional view taken along the line BB of FIG. 1;

FIG. 4 is a cross-sectional view showing the configuration of a conventional high melting point substance evaporation device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Vacuum chamber 2 High melting point metal rod electrode 3 High frequency power supply 4 Plasma 5 Vacuum pump 6 Discharge chamber 7 Gas cylinder 8 Blocking capacitor 9 External DC voltage source 10 Positive ions 11 Direct-acting device 12 Magnet 13 Vapor outlet 14 Film substrate 17 Metal vapor

Front page continued (72) Inventor Mitsuo Kato 4-6-22 Kannon Shinmachi, Nishi-ku, Hiroshima City Mitsubishi Heavy Industries, Ltd. Hiroshima Research Institute (72) Inventor Kuniyuki Kajinishi 4-22 Kannon-shinmachi, Nishi-ku, Hiroshima City Mitsubishi Heavy Industries Hiroshima Laboratory Co., Ltd.

Claims (1)

[Claims] 1. In a device for heating and evaporating a high melting point substance having conductivity, a rod-shaped high frequency electrode made of a high melting point substance to be vaporized is disposed inside to provide a discharge space, a vacuum chamber and the chamber and the high frequency wave. In the space between the electrodes, a plurality of magnets having different magnetic poles, which are alternately arranged so as to surround the high-frequency electrode and are arranged adjacently to each other, are provided, and the outer peripheral wall of the vacuum chamber is used as a ground electrode. High melting point vaporizer.