MICROWAVE EMISSION MECHANISM, MICROWAVE PLASMA SOURCE AND SURFACE WAVE PLASMA PROCESSING APPARATUS

• US 20140361684A1
• Filed: 12/14/2012
• Published: 12/11/2014
• Est. Priority Date: 01/27/2012
• Status: Active Grant

• Current Assignee: Tokyo Electron Limited
• Original Assignee: Tokyo Electron Limited
• Inventors: Ikeda, Taro, Miyashita, Hiroyuki, Osada, Yuki, Fujino, Yutaka, Komatsu, Tomohito
• Granted Patent: US 9,520,272 B2
• Time in Patent Office: Days
• US Class Current: 315/34
• CPC Class Codes: H01J 37/32192 Microwave generated discharge H01J37/32357, H01J37/32366, H01J37/32394, H01J37/32403 take precedence
• CPC Class Codes: H01J 37/32201 Generating means
• CPC Class Codes: H01J 37/3222 Antennas
• CPC Class Codes: H01J 37/32229 Waveguides
• CPC Class Codes: H01J 37/32266 Means for controlling power transmitted to the plasma
• CPC Class Codes: H05H 1/46 using applied electromagnetic fields, e.g. high frequency or microwave energy H05H1/26 takes precedence
• CPC Class Codes: H05H 1/4615 using surface waves
• CPC Class Codes: H05H 1/4622 using waveguides
• CPC Class Codes: H05H 1/463 using antennas or applicators

Abstract

A microwave emission mechanism includes: a transmission path through which a microwave is transmitted; and an antenna section that emits into a chamber the microwave transmitted through the transmission path. The antenna section includes an antenna having a slot through which the microwave is emitted, a dielectric member through which the microwave emitted from the antenna is transmitted and a closed circuit in which a surface current and a displacement current flow. A surface wave is formed in a surface of the dielectric member. The closed circuit has at least: an inner wall of the slot; and the surface and an inner portion of the dielectric member. When a wavelength of the microwave is λ₀, a length of the closed circuit is nλ₀±δ, where n is a positive integer and δ is a fine-tuning component including 0.

Claims

1. A microwave emission mechanism for emitting into a chamber a microwave generated by a microwave generation mechanism, in a plasma processing apparatus for performing plasma processing by generating a surface wave plasma in the chamber, the microwave emission mechanism comprising:

a transmission path through which the microwave is transmitted, the transmission path including a cylindrical outer conductor and an inner conductor coaxially disposed within the outer conductor; and

an antenna section configured to emit into the chamber the microwave transmitted through the transmission path,

wherein the antenna section includes;

an antenna having a slot through which the microwave is emitted;

a dielectric member through which the microwave emitted from the antenna is transmitted, a surface wave being formed on a surface of the dielectric member; and

a closed circuit in which a surface current and a displacement current flow, the closed circuit having at least an inner wall of the slot and the surface and an inner portion of the dielectric member, and

wherein when a wavelength of the microwave is λ

₀, a length of the closed circuit is nλ

₀±

δ

, where n is a positive integer and δ

is a fine-tuning component including 0.

2. The microwave emission mechanism of claim 1, wherein a thickness of the slot is determined such that the length of the closed circuit becomes nλ

₀±

δ

.

3. The microwave emission mechanism of claim 1, wherein the slot is filled with a dielectric material.

4. The microwave emission mechanism of claim 1, wherein a thickness of the slot is set to be relatively thick while setting a thickness of the dielectric member to be relatively thin such that the length of the closed circuit becomes nλ

₀±

δ

.

5. A microwave plasma source, comprising:

a microwave generation mechanism configured to generate a microwave; and

a microwave emission mechanism configured to emit the generated microwave into a chamber,

wherein the microwave is emitted into the chamber to generate a surface wave plasma of a gas supplied into the chamber,

wherein the microwave emission mechanism includes;

a transmission path through which the microwave is transmitted, the transmission path including a cylindrical outer conductor and an inner conductor coaxially disposed within the outer conductor; and

an antenna section configured to emit into the chamber the microwave transmitted through the transmission path,

wherein the antenna section includes;

an antenna having a slot through which the microwave is emitted;

a dielectric member through which the microwave emitted from the antenna is transmitted, a surface wave being formed on a surface of the dielectric member; and

a closed circuit in which a surface current and a displacement current flow, the closed circuit having at least an inner wall of the slot and the surface and an inner portion of the dielectric member, and

wherein when a wavelength of the microwave is 0.4, a length of the closed circuit is nλ

₀±

δ

, where n is a positive integer and δ

is a fine-tuning component including 0.

6. The microwave plasma source of claim 5, wherein the microwave emission mechanism is provided in plural numbers.

7. The microwave plasma source of claim 5, wherein in the microwave emission mechanism, a thickness of the slot is determined such that the length of the closed circuit becomes nλ

₀±

δ

.

8. The microwave plasma source of claim 5, wherein the slot of the microwave emission mechanism is filled with a dielectric material.

9. The microwave plasma source of claim 5, wherein in the microwave emission mechanism, a thickness of the slot is set to be relatively thick while setting a thickness of the dielectric member to be relatively thin such that the length of the closed circuit becomes nλ

₀±

δ

.

10. A surface wave plasma processing apparatus, comprising:

a chamber configured to accommodate a substrate to be processed;

a gas supply unit configured to supply a gas into the chamber; and

a microwave plasma source configured to emit a microwave into the chamber to generate a surface wave plasma of the gas supplied into the chamber, the microwave plasma source including a microwave generation mechanism for generating the microwave and a microwave emission mechanism for emitting the generated microwave into the chamber,

wherein the substrate in the chamber is processed by the surface wave plasma,

wherein the microwave emission mechanism includes;

a transmission path through which the microwave is transmitted, the transmission path including a cylindrical outer conductor and an inner conductor coaxially disposed within the outer conductor; and

an antenna section configured to emit into the chamber the microwave transmitted through the transmission path,

wherein the antenna section includes;

an antenna having a slot through which the microwave is emitted;

a dielectric member through which the microwave emitted from the antenna is transmitted, a surface wave being formed on a surface of the dielectric member; and

a closed circuit in which a surface current and a displacement current flow, the closed circuit having at least an inner wall of the slot and the surface and an inner portion of the dielectric member, and

wherein when a wavelength of the microwave is λ

₀, a length of the closed circuit is nλ

₀±

δ

, where n is a positive integer and δ

is a fine-tuning component including 0.

11. The surface wave plasma processing apparatus of claim 10, wherein the microwave plasma source includes a plurality of microwave emission mechanisms.

12. The surface wave plasma processing apparatus of claim 10, wherein in the microwave emission mechanism, a thickness of the slot is determined such that the length of the closed circuit becomes nλ

₀±

δ

.

13. The surface wave plasma processing apparatus of claim 10, wherein the slot of the microwave emission mechanism is filled with a dielectric material.

14. The surface wave plasma processing apparatus of claim 10, wherein in the microwave emission mechanism, a thickness of the slot is set to be relatively thick while setting a thickness of the dielectric member to be relatively thin such that the length of the closed circuit becomes nλ

₀±

δ

.