JPS6222652B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in an activated gas generating device used to perform various treatments by irradiating an activated gas onto an object to be treated.

2. Description of the Related Art Conventionally, attempts have been made to perform various treatments by irradiating a workpiece with a reactive gas generated and activated using plasma generated by vacuum discharge. An example of a conventional device will be explained with reference to FIG. There is a reactor 7 in which a workpiece 11 is placed, the reactor 7 is kept airtight with a gasket 9 and a lid 10, and the inside pressure is reduced to a vacuum degree of Torr or less, and an exhaust device 8 is connected to the reactor 7 through an exhaust pipe 7b. The reactor 7 is provided with a gas supply pipe 7a and an exhaust pipe 7b with the object to be treated 11 in between, and a reactant gas source is connected to the gas supply pipe 7a via a flow rate control valve 12. Also, gas supply pipe 7
a passes through the waveguide 5, and the reactant gas supplied by the microwave power generated from the microwave oscillator 1 is activated in the plasma region 7c. The matching device 4 and the sliding short-circuit plate 6 are used to efficiently absorb microwave power into the reaction gas. The power monitor 3 is for detecting the degree of absorption of microwave power, and the degree of absorption is indicated by an indicator 3a. The activated reaction gas is sucked in the direction of the exhaust device 8 and hits the object to be treated 11 for surface treatment.

When using the conventional device as described above to activate the reaction gas in the gas supply pipe 7a using the waveguide 5 and applying it to the object to be processed 11, there is a limit to the diameter of the supply pipe, and the inside of the reactor The amount of activated gas supplied to is not very large, and if the object to be processed is small, it will be processed relatively uniformly, but if it is large, it will not be able to be processed uniformly. Further, the gas supply pipe 7a is generally made of a dielectric material such as quartz which is not easily corroded by the activated gas, but this is easily damaged and expensive.

Furthermore, the conventional device described above also has the disadvantage that radio wave leakage increases experimentally when the activation gas pressure becomes approximately 0.5 Torr or less.

The present invention is intended to eliminate such drawbacks, and provides an activated gas generation device that can obtain a relatively large amount of activated reaction gas.

Embodiments of the present invention will be described below with reference to the drawings. In the device according to the embodiment of the present invention shown in FIGS. 2 and 3, the microwave power generated in the microwave oscillator 101 is transmitted to the oscillator protection isolator 102, the power monitor 103, the matching box 104, and the corner 105.
The signal is transmitted to the feeding waveguide 107 via. The feeding waveguide 107 has a rectangular shape, and its H (magnetic field) plane 10
A gas supply pipe 108 made of a conductor for supplying a reaction gas in parallel with the E (electric field) plane 107a is inserted from the E (electric field) plane 107a to the center. A reactant gas supply source 110 is connected to the other end of the supply pipe 108, and the flow rate of the reactant gas can be adjusted by a flow rate control valve 109. An airtight plate 106 made of a dielectric material such as ceramic or quartz, which allows microwave power to pass through but not gas, is airtightly provided between the feeding waveguide 107 and the corner 105. The terminal end is connected to a vacuum container 111 so that gas can flow therethrough. A shield plate 121, such as a punched metal plate, is installed near the entrance of the vacuum container 111 to block microwaves and allow gas to pass through. A mounting table 114 for placing the object to be processed 113 is provided inside the container, and an exhaust pipe 115 and an exhaust device 116 for exhausting the inside of the vacuum container 111 are connected to the side opposite to the waveguide. ing. The current plate 112 is used to uniformly irradiate the object 113 with activated reaction gas.

Now, with such an apparatus of the present invention, the workpiece 11
3, the object to be processed 113 is placed on the mounting table 11.
4, the exhaust device 116 is operated to evacuate the inside of the vacuum container 111 to a degree of vacuum of 10 ^-1 Torr or less.
Thereafter, the reactive gas to be activated is fed from the gas supply source 110, and the flow rate control valve 109 is adjusted to create a vacuum of 10 to
Set to 10 ^-1 Torr. Thus the microwave oscillator 1
01 to generate microwave power, isolator 102, power monitor 103, matching box 1
04, it is transmitted to the feeding waveguide 107 through the corner 105 to activate the reaction gas in the feeding waveguide 107. The activated reaction gas is removed from the exhaust device 116.
It is sucked in the direction, and on the way, it hits the object to be processed 113 and the intended processing is performed. In addition, matching box 10
Needless to say, the microwave power can be efficiently absorbed into the reaction gas by adjusting the step 4.

By using the device of the present invention as described above, it is possible to activate the reactive gas without using expensive and easily damaged quartz materials, and since the waveguide itself constitutes the plasma region, it is possible to activate the reactive gas. It has a large volume and can obtain a large amount of activated gas, making it suitable for processing large processing areas. Since the gas flows along the direction of microwave transmission, it reliably passes through the high electric field region, which has the advantage of more reliable gas activation and no leakage of radio waves. If the gas supply pipe is inserted from the E side of the waveguide, it will not have any adverse effect on the microwave propagation within the waveguide.
In addition, if the supply pipe is opened at the center of the waveguide, in the case of TE ₀₁ mode, the gas is emitted at the position where the electric field is maximum, which has the advantage of ensuring reliable excitation.

Note that the shape and dimensions of the tip of the feeding waveguide are
As shown in the figure, the width a of the H surface 107b is tapered to be 1/2 or less than the wavelength used for the microwave, and the electric field is increased to effectively absorb the microwave power into the reaction gas. It's okay. As a result, the tip is cut off and there is no electric field inside the container. Note that in this case, the feeding waveguide 107
It is desirable to cool the walls of a with water, high pressure air, etc.

The gas supply pipe 108 may be inserted from the center of the H-plane 107b of the waveguide, and in this case, it is necessary to form the gas supply pipe from a dielectric material.

[Brief explanation of the drawing]

FIG. 1 is a schematic cross-sectional view showing a conventional example, FIG. 2 is a schematic cross-sectional view showing an embodiment of the present invention, FIG. 3 is a cross-sectional view of a feeding waveguide, and FIG. 4 is a schematic cross-sectional view showing an embodiment of the present invention. FIG. 3 is a sectional view of a main part showing an example. 10... Microwave oscillator, 106... Airtight plate, 107... Power supply waveguide, 111... Vacuum container, 113... Processing object, 116... Exhaust device,
110...Gas supply source.

Claims (1)

[Claims] 1. A microwave oscillation source, a vacuum container that accommodates the object to be processed and is connected with an evacuation device so that the inside can be depressurized, and a microwave power is introduced from the oscillation source and a terminal end communicates with the vacuum container. a gas supply pipe that supplies the reaction gas so that plasma is generated by the reaction gas supplied into the power supply waveguide and the microwave power; 1. An activated gas generation device comprising means for supplying microwave power between a position for supplying a reactive gas and the microwave oscillation source and for airtightly separating the reactive gas.