JP2000073188A - Plasma treating apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a plasma treating apparatus less liable to cause defective treatment, capable of reducing maintenance frequency and stably performing uniform gas introduction. SOLUTION: A gas passage from a gas feed hole 9 to a gas blowoff hole 12 in a vacuum vessel 1 is a monolithic passage comprising only an upper lid 7. The corrosion of a gas reservoir 10 due to an electric discharge at the contact part of two members is prevented and defective surface treatment due to the scattering of fine particulates liberated by corrosion together with gas on the surface of a substrate to be treated is prevented. Uniform gas introduction is stably performed by hermetically sealing the gas reservoir 10 with an O ring 21.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ICP (Inductive Induction) such as a dry etching apparatus, a sputtering apparatus, and a CVD apparatus used for manufacturing a semiconductor or a liquid crystal display device (LCD).
The present invention relates to an inductively coupled plasma (Plasma) type processing apparatus.

[0002]

2. Description of the Related Art In recent years, in a plasma processing apparatus for a silicon substrate in a semiconductor manufacturing apparatus, an ICP method has been used due to a demand for fine processing performance.

FIG. 2 shows the structure of a conventional ICP dry etching apparatus. In FIG. 2, reference numeral 1 denotes a vacuum container, and 2 denotes a vacuum exhaust pump for exhausting air in the vacuum container 1.
Reference numeral 3 denotes a coil mounted on a quartz plate 4 constituting the upper surface of the vacuum vessel 1. A high-frequency power supply 5 is connected at the center, and an outer peripheral end is connected to a ground 6.

[0004] Reference numeral 7 denotes an upper cover of the vacuum vessel 1, on which the quartz plate 4 is placed via an O-ring 8.
A gas supply port 9 is formed on the outer peripheral surface of the upper lid 7, and a gas reservoir 10 communicating with the gas supply port 9 is formed along the inner peripheral surface. Reference numeral 11 denotes a gas diffusion ring which is attached to the inner peripheral surface of the upper lid 7 and forms the inner peripheral surface of the gas reservoir 10. A plurality of gas outlets 12 communicating the inner peripheral surface with the gas reservoir 10 are formed through the gas diffusion ring 12. I have.

Reference numeral 13 denotes a silicon wafer as a substrate to be processed. Reference numeral 14 denotes a lower electrode, which is mounted on the insulating plate 15,
It is connected to the. An insulating ring 19 is provided on the outer periphery of the lower electrode 14. Further, a cooling water passage 20 is formed inside the lower electrode 14 so as to circulate the cooling water.

The operation of the dry etching apparatus configured as described above will be described. First, the silicon wafer 13 is placed on the lower electrode 14, and the air in the vacuum chamber 1 is exhausted by the vacuum pump 2. Next, a small amount of etching gas is introduced from the gas supply port 9, and is uniformly diffused into the vacuum chamber 1 through the gas reservoir 10 and the gas outlet 12. Then, a high frequency is applied from the high frequency power supplies 5 and 18 to generate plasma in the vacuum vessel 1 and the silicon wafer 13
Is etched.

Since the plasma is high in temperature, the silicon wafer 13 is simultaneously heated during the etching, but the heat of the silicon wafer 13 is transmitted to the lower electrode 14 cooled by the cooling water in the cooling water passage 20 and is radiated. In addition, it is possible to prevent the silicon wafer 13 from being overheated by the heat of the plasma, thereby changing the quality of the resist and causing poor etching. Further, since the temperature of the silicon wafer 13 is kept constant, the etching characteristics are well maintained.

When the reaction product adheres after the etching process, the gas diffusion ring 11 is removed and the gas reservoir 10 is maintained.

[0009]

However, in the above-described conventional configuration, a potential difference is generated at the contact portion between the gas diffusion ring 11 and the upper lid 7 due to the inductive coupling of the ICP, and a discharge occurs to cause a gap between the gas diffusion ring 11 and the upper lid 7. 10 gas reservoirs were corroded.

As a result, there is a problem that fine particles released from the member due to corrosion are scattered together with the gas from the gas outlet 12 onto the etching surface of the substrate to be processed, thereby causing an etching defect. In particular, when a halide gas is used, poor etching due to dust generation appears remarkably. The corroded gas diffusion ring 11 and the upper lid 7 need to be replaced, and the frequency of maintenance has increased.

In addition, since the gas reservoir 10 of the upper lid 7 is not made to have a closed structure, the gas escapes from between the upper lid 7 and the gas diffusion ring 11 so that there is a problem that uniform gas cannot be introduced.

The present invention has been made in consideration of the above-described conventional problems, and has as its object to provide a plasma processing apparatus that can reduce processing defects, reduce maintenance frequency, and stably perform uniform gas introduction.

[0013]

SUMMARY OF THE INVENTION A plasma processing apparatus according to the present invention comprises a vacuum vessel, vacuum exhaust means for exhausting air inside the vacuum vessel, a coil and an electrode for generating inductively coupled plasma, and a gas in the vacuum vessel. A gas supply means for supplying gas to the supply port and filling the gas into the vacuum container from the gas outlet, and a gas path from the gas supply port in the vacuum container to the gas outlet via the gas reservoir. The discharge does not occur at the contact portion of the two members and does not corrode the gas pool, and the fine particles released by the corrosion scatter with the gas on the surface of the substrate to be processed, resulting in poor surface treatment. Can be prevented, and the frequency of maintenance can be reduced.

When the gas reservoir is sealed with an elastic body,
Since gas does not escape from the gas reservoir, uniform gas introduction can be stably performed.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of an ICP processing apparatus according to the present invention will be described below with reference to FIG. The same components as those of the conventional example described with reference to FIG. 2 are denoted by the same reference numerals, and the description thereof is referred to. Here, only the differences will be described.

In this embodiment, the configuration of the gas reservoir 10 and the gas outlet 12 is different from the conventional example as follows. In this embodiment, there is no gas diffusion ring 11, a gas reservoir 10 is formed between the inner peripheral surface and the outer peripheral surface of the upper lid 7 so as to be recessed from the upper end surface, and a plurality of gas outlets are formed in the inner peripheral surface of the upper lid 7. 12 is formed and communicates with the gas reservoir 10. An O-ring 21 is mounted on the upper end of the gas reservoir 10 to seal the gas reservoir 10 and the quartz plate 4.

Next, an etching operation by the ICP processing apparatus having the above configuration will be described. First, the silicon wafer 13 to be processed is placed on the lower electrode 14, and the vacuum pump 2 exhausts air from the vacuum vessel 1. Next, a small amount of the etching gas introduced from the gas supply port 9 is uniformly diffused into the vacuum vessel 1 through the gas reservoir 10 and the gas outlet 12. Then, a high-frequency voltage is applied by the high-frequency power supplies 5 and 18 to generate plasma in the vacuum vessel 1 and the silicon wafer 13 is etched.

At this time, since the gas supply port 9 to the gas blowing port 12 have an integral structure consisting of only the upper lid 7, inductive coupling by ICP does not occur in this portion,
No corrosion occurs in the gas reservoir 10 and the gas outlet 12.

Further, since the gas reservoir 10 is sealed by the O-ring 21, gas is introduced into the vacuum vessel 1 only from the gas outlet 12, so that uniform gas introduction can be stably performed.

If the reaction products adhere after the etching process, the O-ring 21 is removed and the gas is easily collected.
0 maintenance can be performed.

In the above embodiment, an example of the dry etching process has been described. However, the present invention can be similarly applied not only to a dry etching apparatus but also to a sputtering apparatus or a CVD apparatus.

[0022]

According to the plasma processing apparatus of the present invention, as described above, the gas path from the gas supply port to the gas outlet through the gas reservoir in the vacuum vessel is integrally formed, so that two members are provided. Discharge does not occur in the contact portion and corrodes the gas pool, so that fine particles liberated by the corrosion can be prevented from scattering on the surface of the substrate to be processed together with the gas to generate surface treatment defects, and maintenance frequency can be reduced. .

When the gas reservoir is sealed with an elastic body,
Since gas does not escape from the gas reservoir, uniform gas introduction can be stably performed.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a schematic configuration of an embodiment of a plasma processing apparatus according to the present invention.

FIG. 2 is a cross-sectional view illustrating a schematic configuration of a conventional plasma processing apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Vacuum container 2 Vacuum pump 3 Coil 7 Top cover 9 Gas supply port 10 Gas reservoir 12 Gas outlet 14 Lower electrode 21 O-ring (elastic body)

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01L 21/3065 H01L 21/302 B 5F103 (72) Inventor Masaki Suzuki 1006 Odakadoma, Kadoma City, Osaka Matsushita Electric F-term (reference) in Sangyo Co., Ltd.

Claims (2)

[Claims] 1. A vacuum vessel, a vacuum exhaust means for exhausting air inside the vacuum vessel, a coil and an electrode for inductively coupled plasma generation, and a gas supply port for supplying a gas to a gas supply port of the vacuum vessel from a gas outlet. A plasma processing apparatus having gas supply means for filling a gas into a vacuum vessel, wherein a gas path from a gas supply port to a gas outlet through a gas reservoir in the vacuum vessel is integrally formed. Plasma processing apparatus. 2. The plasma processing apparatus according to claim 1, wherein the gas reservoir is sealed with an elastic body.