JPH0562796A - Microwave plasma device - Google Patents

Abstract

PURPOSE:To generate plasma having a uniform density and process the surface of a sample at a uniform speed. CONSTITUTION:A microwave waveguide 14 guiding microwaves to a plasma generation chamber 11 is provided, and an electromagnetic coil 18 is arranged around the plasma generation chamber 11. The plasma generation chamber 11 is made of a microwave transmittable material, one end of the microwave waveguide 14 is connected to a microwave oscillator, and the other end surrounds the plasma generation chamber 11. A dielectric substance 13 is filled at the portion of the microwave waveguide 14 surrounding the plasma generation chamber 11.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a microwave plasma device, and more particularly to a microwave plasma guide chamber having a microwave waveguide for guiding microwaves, in which an electromagnetic coil is arranged around the plasma generation chamber. Wave plasma device.

[0002]

2. Description of the Related Art A method of generating plasma by electron cyclotron resonance (hereinafter referred to as "ECR") excitation is capable of generating plasma with high ionization degree at low gas pressure, wide selection of ion energy, and large ion. It has advantages such as high current flow and excellent ion flow directivity and uniformity. For this reason, research and development have been vigorously pursued as indispensable for processes such as thin film formation and etching in the manufacture of high-frequency semiconductor devices.

FIG. 3 is a sectional view schematically showing an etching apparatus as an example of a conventional microwave plasma apparatus, and reference numeral 41 in the figure denotes a plasma generation chamber. The plasma generation chamber 41 includes a cylindrical peripheral wall 41b having a cooling water passage 41a formed therein, an upper wall 41c, and a lower wall 41.
The upper wall 41c has a microwave introduction port 42 formed substantially in the center thereof. The microwave introduction port 42 is sealed by a microwave introduction window 43 arranged above the microwave introduction port 42, and the lower end of a waveguide 44 is connected to the microwave introduction port 42 through the microwave introduction window 43. ing. The upper end of the waveguide 44 is connected to a microwave oscillator (not shown) so that the microwave generated by the microwave oscillator is guided into the plasma generation chamber 41 through the waveguide 44 and the microwave introduction window 43. Is becoming Further, a gas supply pipe 45 is connected to the upper wall 41c, and an exciting coil 48 is arranged substantially concentrically with the plasma generation chamber 41 around the lower ends of the plasma generation chamber 41 and the waveguide 44. Has been done.

On the other hand, the lower wall 41d of the plasma generation chamber 41
Is formed with a plasma extraction window 46, and the plasma extraction window 46 is provided below the plasma extraction window 46.
Thus, a sample chamber 47 communicating with the plasma generation chamber 41 is provided. A sample table 49 for holding the sample S by an electrostatic chuck or the like is arranged at a position facing the plasma extraction window 46 of the sample chamber 47, and a lower wall of the sample chamber 47 is connected to an exhaust device (not shown). The exhaust port 50 is formed.

When the sample S is subjected to the etching treatment by using the microwave plasma apparatus configured as described above, first, the inside of the plasma generation chamber 41 and the sample chamber 47 is set to a required vacuum degree, and then the plasma generation chamber. After a required gas is supplied into the inside 41 through the gas supply pipe 45, a microwave is introduced into the plasma generation chamber 41 through the waveguide 44 while forming a magnetic field by the exciting coil 48. Then, the gas is resonantly excited by using the plasma generation chamber 41 as a cavity resonator, and plasma is generated in the plasma generation chamber 41. The generated plasma is a divergent magnetic field whose magnetic flux density decreases toward the sample chamber 47 side formed by the exciting coil 45,
It is projected around the sample S in the sample chamber 47, whereby the surface of the sample S is etched.

[0006]

In the above microwave plasma device, a divergent magnetic field is formed by the exciting coil 48, and the charged particles move along the lines of magnetic force, and the ions in the plasma that contribute to etching and film formation are sampled. It is incident on S. However, the microwave introduction port 42 serving as a microwave introduction portion to the plasma generation chamber 41 is localized in the upper central portion of the plasma generation chamber 41, and the plasma extraction window 46 is also formed in the lower central portion of the plasma generation chamber 41. Therefore, the distribution of the plasma density on the surface of the sample S becomes high in the central portion of the sample S, and the central portion having a high plasma density has a high processing speed, so that there is a problem that a uniform film is not formed or etching occurs.

The present invention has been made in view of the above-mentioned problems, and it is possible to uniformly distribute the plasma on the sample surface S, and thus to uniformize the processing speed on the sample surface by the plasma, which is excellent. It is an object of the present invention to provide a microwave plasma device capable of performing shape etching or uniform film formation.

[0008]

In order to achieve the above object, a microwave plasma apparatus according to the present invention comprises a microwave waveguide for guiding a microwave to a plasma generation chamber,
In a microwave plasma device in which an electromagnetic coil is arranged around the plasma generation chamber, while the plasma generation chamber is formed using a microwave permeable material,
One end of the microwave waveguide is connected to a microwave oscillator, and the other end is formed so as to surround the plasma generation chamber, and the microwave waveguide portion surrounding the plasma generation chamber is filled with a dielectric. It is characterized by being.

[0009]

According to the above-mentioned device, in the microwave plasma device having the microwave waveguide for guiding the microwave to the plasma generation chamber and the electromagnetic coil arranged around the plasma generation chamber, the plasma generation chamber Is formed using a microwave permeable material, while one end of the microwave waveguide is connected to a microwave oscillator, the other end is formed to surround the plasma generation chamber,
Since the microwave waveguide portion surrounding the plasma generation chamber is filled with a dielectric, microwaves are spread from the dielectric filled in the tip of the microwave waveguide to almost the entire area of the plasma generation chamber. Introduced, plasma is generated with a uniform density in the plasma generation chamber, and the generated plasma is guided to the sample by the magnetic field. Therefore, plasma having a uniform density reaches the entire surface of the sample, and etching or film formation is performed at a uniform rate.

[0010]

Embodiments of the microwave plasma apparatus according to the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view schematically showing an embodiment of a microwave plasma apparatus according to the present invention.
Indicates a plasma generation chamber formed in a circular shape in plan view, and the plasma generation chamber 11 is formed by a quartz bell jar 12 capable of transmitting microwaves. One end of the microwave waveguide 14 is connected to a microwave oscillator (not shown), and the other end is arranged so as to surround the quartz bell jar 12. The microwave waveguide 14 surrounding the quartz bell jar 12 is filled with a Teflon dielectric 13. The dielectric 13 is sufficient as a dielectric line if it has a certain thickness (for example, about 20 mm), and plasma is generated from the dielectric 13 by reducing the thickness of the dielectric 13 or removing the dielectric 13 in the middle. The microwave radiation to the chamber 11 can be adjusted. Further, the upper end surface of the dielectric 13 is cut obliquely, and by forming the inclined surface 13a in this manner, reflection of microwaves from the microwave oscillator can be reduced. Then, the microwave generated by the microwave oscillator is configured to pass through the quartz bell jar 12 through the microwave waveguide 14 and the dielectric 13 and be guided into the plasma generation chamber 11.

A sample chamber 17 which communicates with the plasma generation chamber 11 through a plasma extraction window 11a is disposed below the plasma generation chamber 11.

A sample table 19 for holding the sample S by an electrostatic chuck or the like is arranged at a position facing the plasma extraction window 11a in the substantially central part of the sample chamber 17, and both sides of the sample table 19 are provided. The exhaust port 20 is formed.

On the other hand, the plasma generation chamber 11 and the microwave waveguide 14 are surrounded by the plasma generation chamber 11 near the lower end portions thereof.
The electromagnetic coil 18 is arranged substantially concentrically with.

In the microwave plasma apparatus constructed as described above, after the sample S is placed on the sample table 19, the insides of the plasma generation chamber 11 and the sample chamber 17 are set to a required degree of vacuum, and then the plasma generation chamber. A required gas is supplied into 11 through a gas supply pipe (not shown). Then, a direct current is passed through the electromagnetic coil 18. Microwaves are guided to the plasma generation chamber 11 via the microwave waveguide 14 and the dielectric 13 to generate plasma in the plasma generation chamber 11. On the other hand, the flow to the electromagnetic coil 18 causes the plasma generation chamber 11
A downward magnetic field is formed uniformly over almost the entire area of
Due to this divergent magnetic field, the plasma is poured onto the sample S at a uniform density.

When microwaves are introduced into the plasma generation chamber 11 from the microwave waveguide 14 while forming the magnetic field in this way, the gas is resonantly excited by using the plasma generation chamber 11 as a cavity resonator and the inside of the plasma generation chamber 11 is excited. The plasma is efficiently generated in a wide area. Further, since the microwave is supplied to the plasma generation chamber 11 at a uniform density by the dielectric 13, plasma is uniformly generated in substantially the entire area of the plasma generation chamber 11, and the ions in the plasma are generated with respect to the sample S. Then, the light is incident at a uniform density, and the surface of the sample S is processed at a uniform speed.

FIG. 2 is a sectional view schematically showing another embodiment of the microwave plasma device according to the present invention.
Reference numeral 1 denotes a hemispherical plasma generation chamber. The plasma generation chamber 21 is formed by a quartz bell jar 22 capable of transmitting microwaves, and one end of a microwave waveguide 24 is disposed so as to surround the quartz bell jar 22. One end of this microwave waveguide 24 is filled with a dielectric 23 made of Teflon, and the end surface of the dielectric 23 on the microwave oscillator side is an inclined surface 23a.
The right end of the microwave waveguide 24 is connected to a microwave oscillator (not shown). Then, the microwave generated by the microwave oscillator is configured to pass through the quartz bell jar 22 through the microwave waveguide 24 and the dielectric 23 and be guided into the plasma generation chamber 21.

A sample chamber 27 communicating with the plasma generation chamber 21 is disposed below the plasma generation chamber 21.

The sample table 1 for holding the sample S by an electrostatic check or the like is provided at a position substantially in the center of the sample chamber 27.
9 is provided, and an exhaust port 30 is provided below the sample table 19.
Are formed.

On the other hand, the plasma generation chamber 21 and the microwave waveguide 24 are surrounded by the plasma generation chamber 21 around the lower end portions thereof.
An electromagnetic coil 28 is arranged substantially concentrically with the above.

Also in the embodiment shown in FIG. 2, FIG.
It is possible to obtain the same effect as that of the embodiment shown in FIG.

[0022]

As is apparent from the above description, in the microwave plasma device according to the present invention, the plasma generation chamber is provided with the microwave waveguide, and the plasma generation chamber is surrounded by the microwave waveguide. In the microwave plasma device provided with an electromagnetic coil, while the plasma generation chamber is formed using a material that can transmit microwaves, one end of the microwave waveguide is connected to a microwave oscillator and the other end thereof is connected. Is formed so as to surround the plasma generation chamber, and the microwave waveguide portion surrounding the plasma generation chamber is filled with a dielectric, so that microwaves may cause the microwave waveguide and the dielectric to be surrounded. Is introduced into the plasma generation chamber through almost the entire area, and plasma is generated in the plasma generation chamber with a uniform density.
Therefore, the plasma is uniformly supplied to the sample surface, and the sample surface can be processed at a uniform rate.

[Brief description of drawings]

FIG. 1 is a schematic sectional view of an embodiment of a microwave plasma device according to the present invention.

FIG. 2 is a sectional view schematically showing another embodiment of the microwave plasma device according to the present invention.

FIG. 3 is a cross-sectional view schematically showing an example of a conventional microwave plasma device.

[Explanation of symbols]

 11, 21 Plasma generation chamber 12, 22 Quartz bell jar 13, 23 Dielectric 14, 24 Microwave waveguide 18, 28 Electromagnetic coil

Claims (1)

[Claims] 1. A microwave plasma apparatus having a microwave waveguide for guiding microwaves to a plasma generation chamber, wherein an electromagnetic coil is arranged around the plasma generation chamber, wherein the plasma generation chamber can transmit microwaves. On the other hand, one end of the microwave waveguide is connected to a microwave oscillator, and the other end is formed so as to surround the plasma generation chamber. A microwave plasma device characterized in that the wave waveguide portion is filled with a dielectric.