JPH10241896A - Plasma generation method and plasma processing apparatus - Google Patents

Abstract

(57) Abstract: The present invention performs plasma processing by efficiently diffusing a small volume of plasma and efficiently supplying the plasma to an object to be processed having a large area. A cylindrical structure made of a dielectric is connected at both ends to a reaction chamber.
A high-density plasma is generated by supplying a helicon wave into the cylindrical structure 21 by winding an antenna 22 to which a high-frequency current is supplied. Each reaction chamber 20 in the route
Spreads in.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma generating method for supplying plasma generated by utilizing electromagnetic waves such as helicon waves to a reaction chamber and the like, and a method of etching, depositing and refining a thin film using plasma. The present invention relates to a plasma processing apparatus for performing quality, dry cleaning, and the like.

[0002]

2. Description of the Related Art Thin film etching, film formation, surface modification, dry cleaning, etc. are performed by exciting a reaction gas by an excitation wave such as a helicon wave and supplying the generated charged particle active species to a substrate. ing.

Here, the helicon wave was Aig in 1960.
It began when rain named waves traveling in low-temperature metals as "helicon waves". The phenomenon of the solid state physics transmitted by the helicon wave is essentially the same as the Heusler wave of the gas plasma.

In this whistler, a noise that sounds like a whistle (whistle) was found in the radio, and this noise came to be called a whistler. Its identity is clockwise circular polarization excited in the ionospheric plasma.

FIG. 5 is a block diagram of such a helicon wave excited plasma processing apparatus. An antenna 2 is wound around a thin quartz tube 1. A high frequency power supply (RF) 3 is connected to the antenna 2 to supply, for example, a 13.56 MHz high frequency current.

A magnetic field coil 4 is provided around the antenna 2.
Are arranged to generate, for example, a weak magnetic field (B to 0.01 T). One end (lower part) of the quartz tube 1 communicates with the reaction chamber (reaction chamber) 5 and the other end (upper part) is closed.

A large number of permanent magnets 6 are arranged on the peripheral wall side of the reaction chamber 5 to suppress the loss of plasma in the reaction chamber 5 and form a surface magnetic field. Further, inside the reaction chamber 5, a substrate 8 is disposed on a table 7, and a high frequency bias (RF bias) 9 is applied.

With such a configuration, when a high-frequency current of, for example, 13.56 MHz is supplied from the high-frequency power supply 3 to the antenna 2, a helicon wave is generated from the antenna 2 and a weak magnetic field ( B to 0.01
10 ¹⁸ to 10 ¹⁹ m at RF power of several kW in T)
^-3 high density plasma 10 is generated. The high-density plasma 10 is diffused into the reaction chamber, and the substrate 8 is subjected to, for example, etching or film formation of a thin film, surface modification, and dry cleaning.

[0009]

When a large glass substrate used for, for example, a liquid crystal display is processed by using such an apparatus, the glass substrate has a very large area, and therefore, the volume of the plasma is large. Needs to be increased and supplied over the entire surface of the glass substrate.

However, in the above device, since the other end of the quartz tube 1 forming the discharge portion is closed, the electrons generated in the plasma collide with the other end of the quartz tube 1, Will disappear. For this reason, the ratio of the electrons that diffuse into the reaction chamber 5 decreases, and the efficiency of the etching process and the like decreases.

In view of the above, in order to spread the plasma 10 and supply the active species to the substrate 8 uniformly with respect to a large glass substrate, a method of generating, diffusing, and transporting the active species is devised. Need to be done.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a plasma generation method capable of efficiently diffusing a small volume of plasma and efficiently supplying the plasma to an object to be processed having a large area.

Another object of the present invention is to provide a plasma processing apparatus capable of efficiently diffusing a small volume of plasma and efficiently supplying the plasma to an object to be processed having a large area to perform plasma processing. .

[0014]

According to the first aspect of the present invention, there is provided a plasma generating method for generating a plasma in a dielectric space having a cylindrical structure and inducing the plasma into a reaction chamber from both ends of the dielectric. According to a second aspect of the present invention, in a plasma processing apparatus for inducing a plasma in a reaction chamber to excite a reaction gas and supplying active species generated by the excitation to a target object to perform a plasma process, A plasma processing apparatus comprising: a cylindrical structure formed into a shape, both ends of which are communicated with a reaction chamber; and excitation means for generating plasma in the cylindrical structure.

According to a third aspect of the present invention, in the plasma processing apparatus according to the second aspect, the cylindrical structure has a plurality of paths each having both ends communicating with the reaction chamber. According to a fourth aspect, in the plasma processing apparatus according to the second aspect, a magnetic field is generated along the axial direction of the cylindrical structure.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. In the plasma generation method of the present invention, plasma is generated in a dielectric space having a cylindrical structure, and the plasma is diffused from both ends of the dielectric into a reaction chamber by a plurality of paths.

FIG. 1 is a block diagram of a helicon wave-excited plasma processing apparatus to which such a plasma generation method is applied. Above the reaction chamber (reaction chamber) 20, there is provided a cylindrical structure 21 for forming the excitation means. This cylindrical structure 21 is formed of a dielectric material, and the central portion is the reaction chamber 2.
Parallel to 0, both ends of which are bent,
Each is connected to the reaction chamber 20.

An antenna 22 is wound around the cylindrical structure 21. A high frequency power supply (RF) 23 is connected to the antenna 22, and a high frequency current of, for example, 13.56 MHz is supplied from the high frequency power supply 23 to generate helicon wave discharge.

As shown in FIG. 2, the antenna 22 is wound in one direction along the outer periphery of the cylindrical structure 21 and then wound in the opposite direction. The directions are indicated by arrows.

A magnetic field coil 24 is arranged around the antenna 22 to generate, for example, a weak magnetic field. The magnetic field generated by the magnetic field coil 24 is generated in a direction along the axial direction of the cylindrical structure 21.

Around the cylindrical structure 21, a solenoid 25 is disposed. The solenoid 25 also generates a magnetic field along the axial direction of the cylindrical structure 21.

On the other hand, on the peripheral wall side of the reaction chamber 20, a number of permanent magnets 26 are arranged to suppress the loss of plasma in the reaction chamber 20, and form a surface magnetic field. A reaction gas inlet 27 is formed in the upper part of the reaction chamber 20, and a glass substrate 29 of, for example, a liquid crystal display is arranged on a table 28 inside the reaction gas inlet 27.
B) High frequency bias (RF bias) 31 through 30
Has been added.

The lower part of the reaction chamber 20 is provided with each exhaust pipe 3.
2 and 33 are connected, and exhaust is performed by each of the pumps 34 and 35. A mesh plate 36 is provided between the table 28 and the inner wall of the reaction chamber 20 toward the exhaust pipes 32 and 33 in the reaction chamber 20.

Next, the operation of the above-configured device will be described. When a high frequency current of, for example, 13.56 MHz is supplied from the high frequency power supply 23 to the antenna 22, the induction electric field induced from the antenna 22 and the coil 2
The helicon wave is generated by the interaction with the magnetic field by 4,
This is supplied into the cylindrical structure 21.

The cylindrical structure 21 includes a magnetic field coil 24.
Is applied along the axial direction of the cylindrical structure 21. In this way, a high-frequency current is supplied from the high-frequency power supply 23 to the antenna 22, and a helicon wave discharge is generated by the antenna 22 and the magnetic field coil 24, so that high-density plasma is generated.

The high-density plasma moves in the direction of the magnetic field generated by the magnetic field coil 24 disposed around the cylindrical structure 21 and further moves in the direction of the magnetic field generated by the solenoid 25. Both ends are supplied to the reaction chamber 20, that is, diffused into the reaction chamber 20 by two paths.

As described above, the high-density plasma is diffused into the reaction chamber 20 by two paths from both ends of the cylindrical structure 21, and for example, a thin film is etched or formed on the glass substrate 29, and the surface is modified. And processing such as dry cleaning.

As described above, in one embodiment,
Both ends of a cylindrical structure 21 formed of a dielectric are connected to the reaction chamber 20, respectively. An antenna 22 to which a high-frequency current is supplied is wound around the cylindrical structure 21, and a helicon wave discharge in the cylindrical structure 21 is performed. Since high-density plasma is generated and the high-density plasma is diffused into the reaction chamber 20 in two paths from both ends of the cylindrical structure 21, the wall against which electrons collide can be reduced to a minimum area, and discharge can be reduced. High-density plasma is applied to the reaction chamber 2 from both ends of the cylindrical structure 21 forming the portion.
It can spread into zero.

Thus, the output supplied to the plasma is
The plasma can be efficiently supplied into the reaction chamber 20, the volume of the plasma can be increased, and for example, the processing efficiency of the large-area glass substrate 29 of the liquid crystal display can be increased.

Also, a magnetic field is generated along the axial direction of the cylindrical structure 21, that is, a magnetic field is applied in a direction parallel to the plasma diffusion direction. Can be reduced, and the processing efficiency of the glass substrate 29 can be further increased.

Therefore, the glass substrate 2 of the liquid crystal display
For a large area substrate such as 9, etching of a thin film,
Film formation, surface modification, dry cleaning, and the like can be performed.
Note that the present invention is not limited to the above-described embodiment, and may be variously modified.

For example, the reaction gas can be excited not only by a helicon wave but also by a microwave, and can be applied to various plasma processes. The plasma is not generated by the helicon wave discharge. For example, as shown in FIG. 3, a coil 40 is wound around the cylindrical structure 21 and an inductive coupling type configuration in which a high frequency power supply 41 is connected to the coil 40 may be employed. Good.

Further, a magnetic field as shown in FIG. 4 may be formed all around the inner wall of the reaction chamber 20 to reduce the loss of electrons and increase the processing efficiency of the glass substrate 29. In addition, the cylindrical structure 21 is configured such that both ends are branched into a plurality of parts, for example, one end is branched into two to form a total of four paths, and the plasma is diffused into the reaction chamber 20 by a plurality of paths. Is also good.

[0034]

As described in detail above, according to the present invention, it is possible to provide a plasma generation method capable of efficiently diffusing a small volume of plasma and efficiently supplying the plasma to a large area object to be processed.

Further, according to the present invention, it is possible to provide a plasma processing apparatus capable of efficiently diffusing a small volume of plasma and efficiently supplying the plasma to an object to be processed having a large area to perform plasma processing.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing an embodiment of a helicon wave excited plasma processing apparatus according to the present invention.

FIG. 2 is a configuration diagram of an antenna for generating a helicon wave.

FIG. 3 is a configuration diagram of an inductive coupling type for generating plasma.

FIG. 4 is a diagram showing another example of a magnetic field generated in a reaction chamber.

FIG. 5 is a configuration diagram of a conventional helicon wave excited plasma processing apparatus.

[Explanation of symbols]

 Reference Signs List 20: reaction chamber, 21: cylindrical structure, 22: antenna, 23: high frequency power supply (RF), 24: magnetic field coil, 26: permanent magnet, 29: glass substrate.

Continuation of the front page (51) Int.Cl. ⁶ Identification code FI H01L 21/3065 H01L 21/31 C 21/31 21/302 B (72) Inventor Masashi Sanka 33 Shinisogocho, Isogo-ku, Yokohama-shi, Kanagawa Prefecture Inside Toshiba Production Technology Laboratory Co., Ltd.

Claims (4)

[Claims] 1. A method for generating plasma, comprising: generating plasma in a dielectric space having a cylindrical structure; and guiding the plasma into a reaction chamber from both ends of the dielectric. 2. A plasma processing apparatus for inducing plasma in a reaction chamber to excite a reaction gas and supplying active species generated by the excitation to an object to be processed to perform plasma processing. A cylindrical structure formed and both ends of which are communicated with the reaction chamber, and an excitation means for generating the plasma in the cylindrical structure,
A plasma processing apparatus comprising: 3. The plasma processing apparatus according to claim 2, wherein the cylindrical structure has a plurality of paths each of which has both ends communicating with the reaction chamber. 4. The plasma processing apparatus according to claim 2, wherein a magnetic field is generated along an axial direction of said cylindrical structure.