JPH0579753B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a microwave plasma processing apparatus,
In particular, the present invention relates to a microwave plasma processing apparatus suitable for forming metal films using low-temperature plasma.

[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 this low-temperature plasma is applied to coating materials, e.g. A microwave plasma processing apparatus that forms a film on a sample by acting on a gas is described in JP-A-56-155535.

[Problem that the invention seeks to solve]

However, in order to form a metal film, such a microwave plasma processing apparatus uses a metal coating material,
For example, when low-temperature plasma is applied to a metal material gas, the metal coating material diffuses to the waveguide side and adheres to the vacuum partition window located in the waveguide section adjacent to the plasma generation chamber, and the metal When the amount of coating material deposited reaches a thickness that exceeds the skin effect of microwaves, there is a problem that microwaves are no longer introduced into the plasma generation chamber and no plasma is generated.

It is therefore an object of the present invention to prevent metal coating materials from adhering to vacuum partition windows.

[Means for solving problems]

In order to achieve this object, the present invention is characterized in that the passage leading the microwave to the plasma generation chamber is bent, and a vacuum partition window for introducing the microwave is provided at the bent part of this passage on the side of the microwave generator. .

[Effect]

With the above configuration, even if the metal coating material is diffused to the waveguide side, most of it will adhere to the bent corner of the passage due to its straightness, and the bent part of the passage on the microwave generator side, In other words, the microwave hardly penetrates to the vacuum partition window for introducing microwaves located in the blind spot.

〔Example〕

Hereinafter, one embodiment of the present invention will be described with reference to the drawings. This embodiment is an example in which a metal material gas is used as the metal coating material, and the present invention is applied to a microwave plasma processing apparatus in which a reaction chamber is configured separately from a plasma generation chamber.

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 difference is fed back to the output current circuit of the magnetron power supply 8 for microwave oscillation 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 bent at an almost right angle through the vacuum partition window 9, and is reflected by the corner metal mesh 11 to change its direction by 90 degrees and is guided. Plasma generation chamber 1 propagates through wave tubes 10b and 10c.
2. That is, the passage that guides the microwave 2 to the plasma generation chamber 12 is bent at a substantially right angle at the waveguide 10a, and the passage that guides the microwave 2 to the plasma generation chamber 12 is bent at a substantially right angle at the waveguide 10a.
is arranged adjacent to the matching device 6 at the bent portion of the passage on the magnetron 1 side. Inside the waveguides 10a to 10c are aperture plates 13a to 13a for vacuum conductance adjustment that also serve as impedance windows and are made of dielectric material such as quartz or ceramics or metal.
13c is placed.

The plasma generation gas supplied through the valve 14 is injected into the plasma generation chamber 12 from a gas injection tube 15 which also serves as a spatter prevention discharge tube, and is mixed with the magnetic field generated by the magnetic field generation electromagnetic coil 16 and the microwave 2. This causes electron cyclotron resonance and generates low-temperature plasma. This low-temperature plasma is introduced into the reaction chamber 1 which has been made into a high vacuum by the exhaust gas 17.
8 and collides with the metal material gas supplied through the valve 19 and injected into the reaction chamber 18 through the gas injection pipe 20 to excite and ionize it;
A thin metal film is generated on the surface of the sample 22 held in the sample holder 21 in the reaction chamber 18 .

The auxiliary exhaust pump 23 has waveguides 10a, 10b,
The metal material gas diffused into 10c is sucked in through the auxiliary exhaust speed adjusting valve 24 and exhausted through the valve 25. Purge gas injection pipe 26
The plasma generating gas supplied through the valve 27 is injected into the vacuum partition window 9 for purging.

According to the microwave plasma processing apparatus as described above, the vacuum partition window 9 is located in the passage on the magnetron 1 side that is bent almost at right angles to the passage on the plasma generation chamber 12 side, that is, in the blind spot. Even if the metal material gas diffuses toward the waveguide, its straightness makes it difficult for it to penetrate to the vacuum partition window 9, which is bent at an approximately right angle. Furthermore, since the vacuum conductance adjustment aperture plates 13a to 13c are provided in the waveguides 10a to 10c, metal material gas is difficult to diffuse, and even if it is diffused, the auxiliary exhaust pump 23
Since the metal gas is exhausted by the vacuum partition window 9, the chances of the metal gas adhering to the vacuum partition window 9 are greatly reduced.
Furthermore, since plasma generation gas is injected into the vacuum partition window 9 for purging by the gas injection pipe 26, the pressure in this area is high, and therefore there is no chance for the metal material gas to reach the vacuum partition window 9. is further reduced.

〔Effect of the invention〕

As described above, in the present invention, the vacuum partition window for introducing microwaves is provided at the bent part on the microwave generator side of the passage leading the microwave to the plasma generation chamber, so that the metal coating material is diffused toward the waveguide side. can be prevented from adhering to this vacuum partition window for introducing microwaves, and therefore plasma can be stably generated in a microwave plasma processing apparatus using a metal coating material.

[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. DESCRIPTION OF SYMBOLS 1... Magnetron, 2... Microwave, 9... Vacuum partition window, 10a-10c... Waveguide, 12... Plasma generation chamber.

Claims (1)

[Claims] 1 Microwaves generated by a microwave generator are guided to a plasma generation chamber via a waveguide to generate low-temperature plasma using electron cyclotron resonance, and this low-temperature plasma is applied to the metal coating material to form a metal film on the sample. In the microwave plasma processing apparatus to be formed, a passage leading the microwave to the plasma generation chamber is bent, and a vacuum partition window for introducing microwaves is provided at the bent part of the passage on the side of the microwave generator. Microwave plasma processing equipment.