Directional coupler for use in a substrate processing apparatus, where the directional coupler includes a coaxial line coupled to a conductor on a substrate

Patent metadata

Field	Value
Publication number	US-11569558-B2
Application number	US-202117155618-A
Country	US
Kind code	B2
Filing date	Jan 22, 2021
Priority date	Jan 29, 2020
Publication date	Jan 31, 2023
Grant date	Jan 31, 2023

Abstract

A directional coupler includes: a hollow coaxial line including a central conductor forming a main line and an outer conductor surrounding the central conductor and having an opening formed therein; a dielectric substrate covering the opening and provided with film-shaped ground conductors, wherein a film-shaped ground conductor covers a rear surface of the dielectric substrate facing the central conductor via the opening and a film-shaped ground conductor covers a front surface of the dielectric substrate, respectively, and are grounded; and a coupling line provided on the rear surface of the dielectric substrate in a region surrounded by the ground conductor formed on the rear surface and serving as an auxiliary line, wherein the ground conductor formed on the front surface is provided with a conductor-removed portion in which a portion of a conductor film in a region facing the coupling line via the dielectric substrate is removed.

First claim

What is claimed is:

1. A directional coupler for extracting portions of a high-frequency power, which flows through a main line, via an auxiliary line that is electromagnetically coupled to the main line, the directional coupler comprising:
a hollow coaxial line including a central conductor forming the main line and an outer conductor surrounding the central conductor and having an opening formed therein, wherein the hollow coaxial line is connected to an input terminal and an output terminal for the high-frequency power;
a dielectric substrate covering the opening and provided with film-shaped ground conductors, wherein a film-shaped ground conductor covers a rear surface of the dielectric substrate facing the central conductor via the opening and a film-shaped ground conductor covers a front surface of the dielectric substrate opposite to the rear surface, respectively, and are grounded; and
a coupling line provided on the rear surface of the dielectric substrate at a location facing the central conductor via the opening, and formed in a region surrounded by the ground conductor formed on the rear surface such that the coupling line is electrically isolated from the ground conductor formed on the rear surface and serves as the auxiliary line, wherein the coupling line is connected to extraction terminals from which the portions of the high-frequency power are extracted,
wherein the ground conductor formed on the front surface is provided with a non-conductive region in which a portion of a conductor film in a region facing the coupling line via the dielectric substrate is not formed, and
wherein the non-conductive region is surrounded by the ground conductor formed on the front surface.

2. The directional coupler of claim 1 , wherein the opening is a circular opening formed in a circular shape so as to encompass an entirety of the coupling line.

3. The directional coupler of claim 2 , further comprising a spacer provided between the outer conductor and the dielectric substrate,
wherein an opening is formed in the spacer and the rear surface of the dielectric substrate faces the central conductor via the opening formed in the outer conductor and the opening formed in the spacer.

4. The directional coupler of claim 3 , wherein the ground conductor formed on the front surface and the ground conductor formed on the rear surface are electrically connected to each other via a through hole formed in the dielectric substrate.

5. The directional coupler of claim 4 , wherein the central conductor is configured by a rod-shaped conductor, and the coupling line is configured by an elongated conductor film formed along the rear surface of the dielectric substrate, and
wherein, when viewed from a direction along the front surface and the rear surface of the dielectric substrate, an extending direction of the rod-shaped conductor and an extending direction of the elongated conductor film are parallel to each other, and when viewed above from the front surface of the dielectric substrate, the extending direction of the rod-shaped conductor and the extending direction of the elongated conductor film intersect each other.

6. The directional coupler of claim 5 , wherein the coupling line is formed such that an angle formed by the extending direction of the rod-shaped conductor and the extending direction of the elongated conductor film is a preset intersection angle.

7. The directional coupler of claim 6 , wherein the intersection angle is adjusted by changing a mounting direction of the dielectric substrate with respect to the hollow coaxial line when viewed from the direction facing the front surface of the dielectric substrate.

8. The directional coupler of claim 7 , wherein each of the extraction terminals is connected to one end of an extraction line formed in the non-conductive region on the front surface of the dielectric substrate, and the other end of the extraction line is connected to the coupling line via the through hole formed in the dielectric substrate.

9. The directional coupler of claim 1 , further comprising a spacer provided between the outer conductor and the dielectric substrate,
wherein an opening is formed in the spacer and the rear surface of the dielectric substrate faces the central conductor via the opening formed in the outer conductor and the opening formed in the spacer.

10. The directional coupler of claim 1 , wherein the ground conductor formed on the front surface and the ground conductor formed on the rear surface are electrically connected to each other via a through hole formed in the dielectric substrate.

11. The directional coupler of claim 1 , wherein the central conductor is configured by a rod-shaped conductor, and the coupling line is configured by an elongated conductor film formed along the rear surface of the dielectric substrate, and
wherein, when viewed from a direction along the front surface and the rear surface of the dielectric substrate, an extending direction of the rod-shaped conductor and an extending direction of the elongated conductor film are parallel to each other, and when viewed above from the front surface of the dielectric substrate, the extending direction of the rod-shaped conductor and the extending direction of the elongated conductor film intersect each other.

12. The directional coupler of claim 1 , wherein each of the extraction terminals is connected to one end of an extraction line formed in the non-conductive region on the front surface of the dielectric substrate, and the other end of the extraction line is connected to the coupling line via a through hole formed in the dielectric substrate.

13. The directional coupler of claim 12 , wherein each of the extraction lines is provided with at least one element selected from an element group consisting of a low-pass filter configured to suppress high-frequency components contained in the portions of the high-frequency power, a high-pass filter configured to suppress low-frequency components contained in the portions of the high-frequency power, and an attenuator configured to attenuate a reflected wave from a side of each of the extraction terminals.

14. The directional coupler of claim 12 , wherein each of the extraction lines is formed in the non-conductive region and constitutes a microstrip line with the ground conductor formed on the rear surface and the non-conductive region formed on the front surface defines regions on both sides of the extraction line to form a separation region having a width equal to or greater than a thickness of the dielectric substrate.

15. The directional coupler of claim 12 , wherein each of the extraction lines is formed in the non-conductive region and constitutes a grounded coplanar line between the ground conductor formed on the front surface, and the non-conductive region defines regions on both sides of the extraction line, and the ground conductor formed on the rear surface.

16. The directional coupler of claim 1 , wherein the extraction terminals comprise:
a traveling wave extraction terminal configured to extract a portion of traveling waves of the high-frequency power supplied from the input terminal via the coupling line; and
a reflected wave extraction terminal configured to extract a portion of reflected waves of the high-frequency power output from the output terminal via the coupling line.

17. An apparatus for processing a wafer, the apparatus comprising:
a processing container in which the wafer is disposed;
a processing gas supplier configured to supply a processing gas into the processing container;
a plasma forming part

Assignees

• Tokyo Electron Ltd

Inventors

• Takahashi Isao
• Miyashita Hiroyuki
• Osada Yuki
• Inoue Mitsuya
• Ashida Mitsutoshi

Classifications

• H01P5/183 Primary

  at least one of the guides being a coaxial line · CPC title

• H05H1/46

  using applied electromagnetic fields, e.g. high frequency or microwave energy (H05H1/26 takes precedence) · CPC title

• H01P5/184

  the guides being strip lines or microstrips · CPC title

• H01J37/32577 Primary

  Electrical connecting means · CPC title

• H01J2237/3341

  Reactive etching · CPC title