JPS59208838A - Microwave plasma treating device - Google Patents

Abstract

PURPOSE:To prevent damage due to the generation of heat of a microwave transmitting window, and to treat a sample stably by mounting the transmitting window where the amplitude of an electric field by a standing wave is minimized. CONSTITUTION:A sample 27 is placed on a sample stage 28, a sample treating chamber 21 is evacuated from an exhaust port 22, a microwave oscillator 31 is operated, microwaves are worked to a treating gas in a plasma generating chamber 24 through a wave guide and a transmitting window 30 to generate plasma, a plasma etching gas mainly comprising radicals is introduced into the sample treating chamber 21 from plasma ejecting holes 26, and the sample 27 is etched and treated. Since the microwave transmitting window 30 is mounted where the amplitude of an electric field by standing waves generated in the plasma generating chamber 24 is minimized at that time, the etching rate of the microwave transmitting window 30 consisting of a quartz board is reduced, the life of a device can be lengthened, trouble such as the seizure of an O ring 32 due to a temperature rise in the microwave transmitting window consisting of an alumina material is prevented, and the sample 27 can be treated stably by plasma.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Technical Field of the Invention The present invention relates to improvements in microwave plasma processing equipment.

(b) Prior art and problems When performing conventional plasma processing, it is necessary to avoid damaging the sample, such as a silicon substrate, and to ensure uniform processing of the sample. A microwave plasma processing apparatus is used in which all of the processing chambers are separated by a shielding plate having a predetermined plasma ejection hole (shield hole). A plasma generation chamber 4, which is a part of a waveguide 6, is provided in the upper part of the sample processing chamber 1, which is evacuated. A shielding plate 5 (a part of the waveguide) interposed between the plasma generation chamber 4 and the sample processing chamber 1 serves as a partition wall to separate the two chambers. A plurality of plasma ejection holes 6 (shield holes) are provided to communicate with the compartments. Inside the sample processing chamber 1 is a sample stage 8 on which the sample 7 is placed.
is provided. Further, the plasma generation chamber 4, which is a part of the waveguide, is provided with a gas inlet 9 in a part thereof, and the waveguide 6 and the microwave oscillator 11 having JIS standard dimensions are passed through the microwave transmission chamber 10. are connected as shown. The microwave transmission window 10 is air-sealed with an O-ring 12 as shown in the figure to maintain a vacuum in the plasma generation chamber 4, and is generally made of a material such as quartz or alumina.

When plasma processing the sample 7 using the microwave plasma processing apparatus configured as described above, the sample 7 is placed on the sample stage 8, evacuated from the exhaust port 2, and then pumped through the gas inlet 9. All of the desired processing gases are introduced and the interiors of the plasma generation chamber 4 and sample processing chamber 1 are adjusted to a predetermined degree of vacuum. Next, the microwave oscillator 11 is activated to generate 2.45 G through the waveguide (JIS standard) and the transmission window 10.
The microwave of Hg acts on the processing gas in the plasma generation chamber 4 to generate a total plasma, and the plasma etching gas mainly composed of radio/v is introduced into the multi-sample processing chamber 1 through the plasma nozzle 6, and the sample 7 is Etched.

In this case, a standing wave A is generated in the plasma generation chamber, which is a part of the waveguide, as shown in the figure, but in conventional equipment, special attention must be paid to the location of this standing wave A and the microwave transmission window IDk. Therefore, heat generation due to standing waves in the transmission window 10 was a problem. That is, due to the heat generated by the transmission window 10, for example, carbon tetrafluoride (OF4
), etc., there is a problem that the etching of the transparent window made of quartz or other materials is promoted and the field of the device becomes short. Although it is not etched, it absorbs a large amount of microwaves and cannot be used at high temperatures, causing problems such as burning of the O-ring 12 for vacuum sealing.

(C) Purpose of the Invention The purpose of the present invention was made in view of the above-mentioned problems, and by creating a structure that can minimize the heat generation of the microwave transmission window, it is possible to provide a long-life device that can perform processing more stably than conventional devices. The present invention provides a microwave plasma processing device.

(d) Structure of the Invention In order to achieve all of its objects, the present invention comprises a microwave generator, a waveguide extending from the microwave generator, and a microwave-transmitting device that is a part of the waveguide and that is transparent to microwaves. It is fully equipped with a plasma generation chamber provided with a window, and a sample processing chamber that is in contact with the plasma generation chamber and communicates with it through the plasma ejection hole, and the microwave transmission window has a minimum amplitude of the electric field of the standing wave. All features are that it is located in a position where

(e) Examples of the invention Embodiments of the present invention will be described below with reference to all the drawings.

FIG. 2 is a schematic diagram of a microwave plasma processing apparatus according to an embodiment of the present invention.

In the figure, 21 is a sample processing chamber, and 22 is an exhaust port.

26 is a waveguide having JIS standard dimensions, 24 is a waveguide 'f
25 is a shielding plate.

26 is a plasma ejection hole (shield hole), 27 is a sample, 2
8 is a sample mounting table, 29 is a gas inlet, 60 is a microwave transmission window, and 61 is a microwave generator.

62 indicates an O-ring.

The difference between the microwave plasma processing apparatus according to the embodiment of the present invention and the conventional one is that, as shown in the figure, the microwave transmission window 60 is provided at a position where the amplitude of the electric field of the standing wave B generated in the plasma generation chamber 24 is minimized. It is at the point where That is, since the plasma generation chamber has a waveguide shape, the phase of the standing microwave wave can be calculated at this time, so the electric field amplitude is theoretically []ff/31i
By providing the microwave transmission window 60 (assuming perfect reflection), it has become possible to significantly reduce the amount of heat generated by microwaves compared to conventional devices.

As a result, the etching rate of the microwave transmitting window 30 made of quartz plate can be reduced, making it possible to extend the life of the device.Also, in the case of a microwave transmitting window made of alumina, the 0-link filter 2 will not glare due to temperature rise. Problems such as these were prevented, and stable plasma processing of sample 27 became possible.

(f) As described in detail, according to the present invention, by providing the microwave transmission window at a position where the amplitude of the electric field of the standing wave is minimized, damage to the transmission window due to heat generation is reduced compared to conventional devices. Prevention is the i5J function, and sample processing can be performed stably, and the production life can be extended, which is effective in reducing equipment maintenance costs and at the same time improving the quality of processed samples. .

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of a conventional device, and FIG. 2 is a schematic diagram of an embodiment of the present invention. In the figure, 1 and 21 are sample processing chambers, 2.23 is a waveguide, 4.24 is a plasma generation chamber, 6.26 is a plasma ejection hole, 7.27 is a sample, and 9.29 is a Ganu inlet bag housing. 0 indicates a microwave transmission window, 61 indicates 72 a microwave generator, Ff, 32 indicates an O-ring, and B indicates a standing wave. Figure 1 Figure 2 Figure 9

Claims (1)

[Claims] A microwave generator, a waveguide extending from the microwave generator, a plasma generation chamber forming a part of the waveguide and provided with a microwave transmission window, and a plasma generation chamber in the plasma generation chamber. A microwave plasma, characterized in that it is completely equipped with a sample processing chamber that is in contact with the sample processing chamber and communicates with it via the plasma ejection hole, and the microwave transmission window is provided at a position where the amplitude of the electric field of the standing wave is minimized. Processing equipment.