JPS63137168A - Microwave plasma treatment apparatus - Google Patents

Abstract

PURPOSE:To stably generate plasma without sticking a metallic material to a vacuum partition window, by arranging throttle plates in waveguides for guiding microwaves so as to prevent the diffusion of gases for the metallic material introduced into a reaction chamber toward the window. CONSTITUTION:Microwaves 2 generates by a microwave generator 1 are guided to a plasma generation chamber 12 through waveguides 10a-10c and low temp. plasma is generated. Throttle plates 13a-13c for regulating vacuum conductance are arranged in the waveguides 10a-10c and a vacuum partition window 9 is placed between the plate 13a and the microwave generator 1. The generated plasma is diffused in a reaction chamber 18 to excite and ionize gases for a metallic material introduced into the chamber 18 from a pipe 20 and a film is formed on a substrate 22 in the chamber 18.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a microwave plasma processing apparatus, and particularly to a microwave plasma processing apparatus suitable for forming a gold i film using a metal material gas.

[Conventional technology].

Microwaves guided by a waveguide from a microwave generator are introduced into a plasma generation chamber through a vacuum partition window to generate low-temperature plasma by electron cyclotron resonance, and the low-temperature plasma is introduced into a reaction chamber into which material gas has been injected. A microwave plasma processing device that diffuses and excites and ionizes a material gas to form a film on a sample in a reaction chamber was developed in Japanese Patent Application Laid-Open No. 56-1.
It is described in Publication No. 55535.

[Problem that the invention seeks to solve]

However, in such a microwave plasma processing apparatus, when metal material gas is injected into the reaction chamber in order to form a metal film, the metal material gas injected into the reaction chamber diffuses into the plasma generation chamber side, causing a vacuum in the microwave introduction section. When the metal material gas adheres to the partition window and the amount of the metal material gas adhered reaches a thickness that exceeds the skin effect of the microwave, there is a problem that the microwave is no longer introduced into the plasma generation chamber and no plasma is generated.

Therefore, an object of the present invention is to prevent the metal material gas injected into the reaction chamber from adhering to the vacuum partition window.

[Means for solving problems]

In order to achieve this object, the present invention is characterized in that a vacuum partition window for guiding microwaves into the plasma generation chamber and between the electron cyclotrons is provided for introducing the microwaves.

[Effect]

Even if the metal material gas injected into the reaction chamber is diffused into the plasma generation chamber, the aperture plate acts as a barrier and prevents this metal material gas from penetrating to the vacuum partition window.

〔Example〕

Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

The microwave 2 generated by the oscillation of the magnetron 1 is outputted via a matching device 6 including an isolator 3 for absorbing reflected waves, a power monitor 4 for monitoring the power of input reflected waves, and an automatic matching device 5. Changes in the load-side impedance are detected by the power monitor 4 as an increase in reflected wave power, which is fed back to the automatic matching device 5 via the amplifier 7, where impedance matching is performed by the matching device 6, and further between the incident wave power and the set value. The output of the magnetron power source 8 for microwave oscillation is fed back to the wave circuit via the amplifier 7 to control the oscillation power of the magnetron 1, so that a constant microwave power is always transmitted to the plasma generation chamber. .

The microwave 2 output as described above is introduced into the waveguide 10a through the vacuum partition window 9, is reflected by the corner metal mesh 11, changes its direction by 90 degrees, and propagates inside the waveguides 10b and 10c. and transmitted to the plasma generation chamber 12. A dielectric material such as quartz or ceramics is inside the waveguides 10a to loc.

The plasma generation gas supplied through the valve 14 is injected into the plasma generation chamber 12 from the gas injection tube 15 which also serves as a discharge tube for preventing spatter, and is used to generate a magnetic field! Hei Iile 6
Electron cyclotron resonance is caused by the magnetic field generated by the microwave 2 and the microwave 2, and low-temperature plasma is generated. This low-temperature plasma is diffused into the reaction chamber 18 which has been made into a high vacuum by the exhaust 17, and collides with the metal material gas supplied through the pulp 19 and injected into the reaction chamber 18 through the gas injection pipe 20. is excited and ionized, and the reaction chamber 18
A thin metal film is generated on the surface of the sample 22 held in the sample holder 21 inside.

The auxiliary exhaust pump 23 has a waveguide 10a (10b).

10c) The metal material gas diffused inside is sucked in through the auxiliary exhaust speed adjusting pulp 24 and exhausted through the valve 25. The purge gas injection pipe 26 injects the plasma generation gas supplied through the pulp 27 into the vacuum partition window 9 for purging.

is difficult to diffuse, and even if it is diffused, the plasma generation gas is injected into the inside of the vacuum partition window 9 of the auxiliary exhaust pump 23 for purging purposes by the gas injection pipe 26, so the pressure at the core is high, and therefore the metal material The chances of gas reaching the vacuum partition window 9 are further reduced. By the way, when the conductance apertures L3a to 13c are made of metal, the waveguides 1a to lOc transmit a constant microwave power to the plasma generation chamber 12 as waveguides with a constant load impedance. However, if it is made of a dielectric material, metal material gas will adhere and the load impedance will change.

However, in this case, the reflected wave power is outputted by the power monitor 4 and the change in load impedance is compensated for by the matching box 6. When a dielectric material such as ceramic is used, metal material gas adheres to the conductance aperture plate 13c, changing the impedance.

However, as described above, this change in impedance is detected by the power monitor 4 as an increase in microwave reflected wave power, and the impedance is matched by the matching box 6, so that a constant microwave power can be transmitted to the plasma generation chamber 12. can.

〔Effect of the invention〕

As described above, the present invention prevents the metal material gas from being diffused toward the vacuum partition window by restricting it, thereby preventing the metal material gas from adhering to the vacuum partition window through which microwaves are introduced. Therefore, plasma can be stably generated in a microwave plasma processing apparatus using metal material gas.

[Brief explanation of the drawing]

The figure is a longitudinal sectional side view of a microwave plasma processing apparatus showing an embodiment of the present invention.

Claims (1)

[Claims] 1. Microwaves generated by a microwave generator are guided to a plasma generation chamber through a waveguide to generate low-temperature plasma by electron cyclotron resonance, and the Diffusing low-temperature plasma to excite the material gas,
In a microwave plasma processing apparatus that ionizes and forms a film on a sample in a reaction chamber, a metal material gas is used as the material gas, a vacuum conductance adjustment aperture plate is provided in the waveguide, and the aperture plate and the microwave A microwave plasma processing apparatus characterized in that a vacuum partition window for introducing microwaves is provided between a generator. 2. The microwave plasma processing apparatus according to claim 1, wherein the aperture plate also serves as a microwave impedance window. 3. The microwave plasma processing apparatus according to claim 1, further comprising an auxiliary exhaust device for evacuating the inside of the waveguide between the aperture plate and the vacuum partition window. 4. The microwave plasma processing apparatus according to claim 1, further comprising means for injecting a purge gas near the inside of the vacuum partition window.