JPH076895A - Microwave plasma processing equipment - Google Patents

Abstract

(57) [Abstract] [Purpose] Stable and uniform gas plasma is generated in the plasma generation chamber to improve processing uniformity. [Structure] A means 1 for oscillating a microwave, means 2, 3, 4 for propagating a microwave in a waveguide, and means 9, 10 for dividing a propagating microwave in a waveguide are divided. It comprises means 5 for injecting microwaves into the plasma generation region to generate plasma, means for evacuating the plasma generation region, and means 8 for introducing gas for plasma processing into the plasma generation region.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a microwave plasma processing apparatus, and more particularly to a microwave plasma processing apparatus suitable for manufacturing semiconductor devices and optical parts.

[0002]

2. Description of the Related Art A conventional device is disclosed in Japanese Patent Laid-Open No. 63-72123.
As disclosed in Japanese Patent Laid-Open No. 63-72124 and Japanese Patent Laid-Open No. 63-72124, a metal phase shifter is provided in the microwave waveguide or a part of the waveguide is projected to improve the processing speed. We are trying to eliminate uneven processing.

Further, as described in JP-A-63-73624, by adjusting the dielectric constant distribution of the bell jar corresponding to the surface to be processed of the sample, the plasma density is homogenized and the uniformity of the processing is improved. It was improving.

[0004]

Among the above-mentioned conventional techniques, the techniques described in JP-A-63-72123 and JP-A-63-72124 do not consider the object of microwave propagation. Therefore, it is necessary to change the phase shifter and its equivalent whenever the processing conditions change.

Further, in Japanese Patent Laid-Open No. 63-73624, although the symmetry is secured, it is necessary to process the bell jar itself, and it is not possible to guarantee the change in the dielectric constant due to the consumption of the bell jar during the process. There was a problem.

An object of the present invention is to provide a microwave plasma processing apparatus capable of generating a stable and uniform gas plasma and improving the processing uniformity.

[0007]

The above-mentioned object is divided into a means for oscillating microwaves, a means for propagating microwaves in a waveguide, and a means for dividing a propagating microwave in the waveguide. This is achieved by comprising means for injecting microwaves into the plasma generation region to generate plasma, means for evacuating the plasma generation region, and means for introducing gas for plasma processing into the plasma generation region.

[0008]

The microwave oscillated by the microwave oscillating means propagates in the waveguide by the microwave propagating means,
The propagating microwave is divided by the dividing means in the waveguide, and becomes a microwave of a uniform mode in the waveguide.
The plasma processing gas is made incident into the plasma generation region kept at a predetermined pressure under reduced pressure by the gas introduction means and the vacuum exhaust means, and the plasma processing gas is turned into plasma.
Thereby, the plasma for processing the sample is stably and uniformly generated, and the uniformity of the processing can be improved.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIG. In the microwave plasma processing apparatus of the present invention, in this case, the bell jar 5 is covered by covering the sample table 7 on which the sample 6 is arranged.
Is hermetically provided in the vacuum container. A vacuum exhaust device (not shown) is connected to the vacuum container, and a plurality of gas supply nozzles are evenly provided so as to surround the sample stage 7 toward the bell jar 7. A circular waveguide 4 is provided around the outside of the bell jar 7 so as to surround the bell jar 7. On the side of the bell jar 5 opposite to the sample stage 7 in the circular waveguide 4, there is provided a phase shifter composed of a cylinder 9 and a partition plate 10 for dividing the microwave to form a microwave of a uniform mode. The cylinder 9 is inside the circular waveguide 4 and the circular waveguide 4
It is supported by a plurality of partition plates 10 that are symmetrically arranged so as to be arranged concentrically with. The upper part of the phase shifter of the circular waveguide 4 is formed in a taper shape, and the rectangular waveguide 2 is connected to the opening end that is further narrowed in a taper shape through the conversion waveguide 3. The magnetron 1 is attached to the end of 2.

In the apparatus constructed as described above, the gas for plasma processing is introduced into the bell jar 5 by the gas supply nozzle 8 and is maintained at a predetermined processing pressure by the vacuum exhaust apparatus. The microwave is generated by the magnetron 1, propagates through the short waveguide 2, the conversion waveguide 3, and the circular waveguide 4, and is introduced into a bell jar 5 that constitutes a plasma generation chamber. A sample 6 and a sample table 7 holding the sample 6 are installed under the bell jar 5, and reaction products and unreacted gas in the plasma generation chamber are evacuated through a gap around the sample table 7.

In this case, a phase shifter in which a metal cylinder 9 is fastened to each other by a plurality of partition plates 10 is formed in the circular waveguide 4, and the partition plates 10 are perpendicular to the microwave propagation direction. It is symmetrically installed in the plane including the cylinder 9 and the circular waveguide 4. The number of partition plates 10 is set so that uniform modes of microwaves are generated depending on the dimensions of the circular waveguide 4 and the cylinder 9. The microwave introduced into the circular waveguide 4 is split by this fixed phase shifter and becomes a microwave of a uniform mode and enters the bell jar 5. As a result, microwaves of a uniform mode are always stably incident on the bell jar 5, so that uniform plasma is formed in the plasma generation chamber, and uniform plasma treatment of the sample can be performed.

As described above, according to this embodiment, a gas plasma that enables uniform plasma processing is generated by using microwaves, that is, a phase shifter in which the microwave mode is fixed before entering the plasma generation chamber. Since it can be introduced into the plasma generation chamber by limiting to a uniform mode,
Microwaves in a stable uniform mode can be introduced into the plasma generation chamber, uniform plasma is generated, and there is the effect of preventing uneven processing of the sample, that is, the uniformity of processing can be improved, and the productivity of plasma processing is improved. it can.

In the present embodiment, the cylinder and the circular waveguide are shown. However, a short cylinder and a circular waveguide, a short cylinder and a short waveguide, or a cylinder and a short waveguide are used. It goes without saying that even a combination may be used.

[0014]

According to the present invention, there is an effect that a stable and uniform gas plasma can be generated and the processing uniformity can be improved.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional perspective view of a microwave plasma processing apparatus showing an embodiment of the present invention.

[Explanation of symbols]

1 ... Magnetron, 2 ... Short waveguide, 3 ... Conversion waveguide,
4 ... Circular waveguide, 5 ... Bell jar, 6 ... Sample, 7 ... Sample stand, 8 ... Gas supply nozzle, 9 ... Cylinder, 10 ... Partition plate.

Claims (1)

[Claims] 1. A means for oscillating microwaves, a means for propagating the microwaves in a waveguide, a means for dividing the propagating microwaves in the waveguide, and a plasma for the divided microwaves. Microwave plasma processing, characterized in that it comprises means for injecting plasma into the generation area, means for evacuating the plasma generation area, and means for introducing gas for plasma processing into the plasma generation area. apparatus.