JP2007191762A - Ecr plasma film deposition system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To exclude the generation of hydrogen in a film deposition chamber caused by hydrocarbon used as a film deposition raw material in the conventional ECR (Electron Cyclotron Resonance) plasma film deposition system and its intrusion into a DLC (Diamond Like Carbon) film, and to improve the film quality of the DLC film by an ECR plasma film deposition process. <P>SOLUTION: Fullerene in a vaporizer 21 is heated and vaporized by a vaporization heater 22 and is introduced into a cavity 2 through an introduction path 23 and an introduction path valve 24, and ECR plasma 7 with high purity composed only of carbon ions and ionized electrons is generated by vaporized carbon, a magnetic field generated by an electromagnetic coil 6 and microwaves M. The carbon ions in the ECR plasma 7 are accelerated toward a substrate 9N and are deposited on the surface of the substrate 9N, so as to produce a DLC film. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an ECR (Electron Cyclotron Resonance) plasma film forming apparatus for manufacturing a protective film for a magnetic disk or MR / GMR head.

  In recent years, a hard carbon film having excellent wear resistance and moisture resistance, particularly a DLC film (diamond-like carbon thin film) has been used as a protective film for magnetic disks and MR / GMR heads. There are several methods for forming a DLC film, but the FCVA method (Filtered Cathodic Vacuum Arc method) in which solid carbon is converted into plasma by arc discharge and deposited on the substrate again is the mainstream. Since the FCVA method uses arc discharge with a large current density, the ionization efficiency is also high, and a dense and high hardness DLC film can be produced at a high film formation rate. However, since arc discharge generally lacks stability like glow discharge, there is a big problem that repeated reproducibility of sufficient film thickness cannot be obtained even when film formation is performed under a certain condition.

  As other methods for producing a DLC film, an ECR plasma film formation method and an ECR plasma film formation apparatus using low-pressure glow discharge by electron cyclotron resonance are known. Since the ECR plasma film forming method generally refers to an ECR-CVD (electron cyclotron resonance-chemical vapor deposition) method (see, for example, Patent Document 1), the background art will be described below using an ECR-CVD apparatus.

An example of an ECR-CVD apparatus is shown in FIG. In FIG. 2, for example, a microwave M having a frequency of 2.45 GHz is introduced into a cavity 2 provided on a side surface of the film forming chamber 1 through a waveguide 3 and a window 4 made of a material transparent to radio waves. A plasma gas P is introduced from the gas introduction system G into the film forming chamber 1 through the gas introduction valve 5. The plasma gas P is, for example, a mixed gas of argon (Ar) and methane (CH ₄ ). The plasma gas P generates an electron cyclotron resonance in the cavity 2 by an 875 Gauss magnetic field generated by the electromagnetic coil 6 and an electromagnetic field generated by the microwave M to generate ECR plasma 7. The ECR plasma 7 is produced by ionization of each ion of molecules or atoms in the plasma gas P, that is, ions of CH ₄ or carbon (C) and hydrogen (H) decomposed from Ar and CH ₄ and the plasma gas P. It consists of generated electrons.

Carbon ions in the ECR plasma 7 are extracted from the cavity 2 and deposited as a DLC film on the surface of the substrate 9 on the substrate holder 8. As the plasma gas P, in addition to the above methane, other hydrocarbons such as ethylene (C ₂ H ₄ ) and propane (C ₃ H ₈ ) can be used. The film formation chamber 1 is normally evacuated by a vacuum evacuation system (not shown), and the pressure of the plasma gas P balances the amount of introduced gas and the amount of exhaust gas by controlling the opening of the gas introduction valve 5 and the exhaust speed. Therefore, the optimum value for obtaining the stable ECR plasma 7 is maintained.

JP 2000-277298 A

  The structure of the conventional ECR plasma film forming apparatus and the film forming method of the DLC film are as described above. However, the structure and the method do not have sufficient DLC film quality. That is, in this method, since hydrocarbon such as methane in plasma gas is used as a film forming raw material, there is a problem that hydrogen is mixed in the formed DLC film and a high quality film cannot be obtained. The object of the present invention is to provide means for solving such problems.

  In order to solve the above problems, the present invention provides a film forming chamber, a cavity provided on a side surface of the film forming chamber, into which microwaves are introduced via a waveguide, and an electromagnetic wave provided around the cavity. In an ECR plasma film forming apparatus having a coil and a substrate holder disposed on the surface of which a substrate for depositing a thin film is disposed, a mechanism for vaporizing solid carbon and the vaporized carbon into a cavity Provide a mechanism to introduce. The solid carbon may be fullerene (C60 Fullerene). The mechanism for vaporizing the solid carbon may be a mechanism for vaporizing the solid carbon by heating. In addition, a voltage for controlling the film quality can be applied to the substrate. The substrate holder can also be configured such that the substrate surface can be installed inclined with respect to the cavity axis. Further, the substrate holder can be configured such that the installed substrate can rotate around the axis of the cavity.

  According to the present invention, since ECR plasma can be generated only by vaporized solid carbon without using hydrocarbon as a film forming raw material, hydrogen is not taken into the DLC film, and the film quality of the DLC film is improved. Can be improved. Uniform film formation is possible by tilting the substrate.

  The first feature of the ECR plasma deposition apparatus provided by the present invention is that a mechanism for vaporizing solid carbon and a mechanism for introducing the vaporized carbon into the cavity are provided, and the second feature is that the solid carbon is fullerene. The third feature is that a mechanism for vaporizing solid carbon by heating is provided as a mechanism for vaporizing the solid carbon, and the fourth feature is for film quality control on the substrate. The fifth feature is that the substrate holder is installed so that the substrate surface is inclined with respect to the cavity axis, and the sixth feature is that the substrate holder is the axis of the cavity. The configuration having all these features is the best configuration.

  This will be described with reference to the illustrated example. FIG. 1 is a diagram showing the configuration of one embodiment of the present invention. In FIG. 1, the structure and operation of components having the same reference numerals as those in FIG. 2 are the same as those in FIG. The vaporizer 21 contains solid carbon fullerene (C60 Fullerene) as a film forming raw material. The material is heated and vaporized by the vaporization heater 22, and the cavity is introduced into the cavity via the introduction path 23 and the introduction path valve 24. The ECR plasma 7 is generated without the need to introduce the plasma gas P of FIG. 2 by the electromagnetic field generated by the microwave M and the electromagnetic coil 6. The ECR plasma 7 is composed of fullerene decomposed carbon ions and ionized electrons, and the carbon ions in the ECR plasma 7 are deposited on the substrate 9N on the substrate holder 8N. The substrate holder 8N is disposed in an oblique direction with respect to the ECR plasma 7, and is rotated during film formation by a rotating mechanism (not shown) to improve the uniformity of the film thickness. A bias voltage is applied from the bias power source 25 to the substrate holder 8N, and hence the substrate 9N. By applying a bias voltage, the incident energy of carbon ions incident on the substrate 9N is determined, and by adjusting the bias voltage, the film quality can be controlled and a high-quality DLC film can be obtained. The film forming chamber 1 is constantly evacuated by a vacuum exhaust system (not shown), and the pressure of the vaporized carbon in the cavity 2 is stabilized by controlling the temperature of the vaporizer 21, the opening of the introduction path valve 24, and the exhaust speed. It is kept at an optimum value for obtaining a new ECR plasma 7.

  The present invention is not limited to the above-described embodiments, and various modifications can be given. For example, in FIG. 1, the arrangement of the cavity 2, the waveguide 3, the substrate holder 8N, and other elements is not limited to the illustrated form. For example, depending on the purpose, the surface of the substrate holder 8N may be directly opposed to the ECR plasma 7 and rotation may be omitted, and the introduction location of the introduction path 23 into the cavity 2 can be freely determined. Instead of the vaporizing heater 22, a high frequency may be supplied from an induction heating coil, and the vaporizer 21 and the built-in solid carbon may be heated by induction heating. The present invention includes all of these.

  The present invention relates to an ECR (Electron Cyclotron Resonance) plasma film forming apparatus for manufacturing a protective film for a magnetic disk or MR / GMR head.

It is a figure which shows the structure of the Example of this invention. It is a figure which shows the structure of the conventional ECR plasma film-forming apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Deposition chamber 2 Cavity 3 Waveguide 4 Window 5 Gas introduction valve 6 Electromagnetic coil 7 ECR plasma 8 Substrate holder 8N Substrate holder 9 Substrate 9N Substrate 21 Vaporizer 22 Vaporization heater 23 Introduction passage 24 Introduction passage valve 25 Bias power supply G Gas Introduction system M Microwave

Claims (6)

  A film forming chamber, a cavity provided on a side surface of the film forming chamber, into which microwaves are introduced via a waveguide, an electromagnetic coil provided around the cavity, and a film forming chamber disposed in the film forming chamber; An ECR plasma film forming apparatus provided with a substrate holder on which a substrate for depositing a thin film on a surface is provided, and is provided with a mechanism for vaporizing solid carbon and a mechanism for introducing vaporized carbon into a cavity. Plasma deposition system.   2. The ECR plasma film forming apparatus according to claim 1, wherein the solid carbon is fullerene (C60 Fullerene).   3. The ECR plasma film forming apparatus according to claim 1, wherein the mechanism for vaporizing the solid carbon is a mechanism for vaporizing the solid carbon by heating.   4. The ECR plasma film forming apparatus according to claim 1, wherein a voltage for controlling film quality is applied to the substrate.   2. The ECR plasma deposition apparatus according to claim 1, wherein the substrate holder is configured so that the substrate surface can be inclined with respect to the axis of the cavity.   2. The ECR plasma deposition apparatus according to claim 1, wherein the substrate holder is configured such that the installed substrate can rotate about the axis of the cavity.

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