High efficiency triple-coil inductively coupled plasma source with phase control

Patent metadata

Field	Value
Publication number	US-10271416-B2
Application number	US-201213657232-A
Country	US
Kind code	B2
Filing date	Oct 22, 2012
Priority date	Oct 28, 2011
Publication date	Apr 23, 2019
Grant date	Apr 23, 2019

Abstract

A plasma processing apparatus may include a process chamber having an interior processing volume, first, second and third RF coils disposed proximate the process chamber to couple RF energy into the processing volume, wherein the second RF coil disposed coaxially with respect to the first RF coil, and wherein the third RF coil disposed coaxially with respect to the first and second RF coils, at least one ferrite shield disposed proximate to at least one of the first, second or third RF coils, wherein the ferrite shield is configured to locally guide a magnetic field produced by an RF current flow through the first, second or third RF coils toward the process chamber, wherein the plasma processing apparatus is configured to control a phase of each RF current flow through each of the of the first, second or third RF coils.

First claim

The invention claimed is:

1. A plasma processing apparatus, comprising:
a process chamber having an interior processing volume;
a first RF coil disposed proximate to the process chamber to couple RF energy into the processing volume;
a second RF coil disposed proximate to the process chamber to couple RF energy into the processing volume, the second RF coil disposed coaxially with respect to the first RF coil;
a third RF coil disposed proximate to the process chamber to couple RF energy into the processing volume, the third RF coil disposed coaxially with respect to the first and second RF coils;
wherein at least one of the first, second and third RF coils is coupled to a coil actuator;
at least one magnetic field confinement shield coupled to a shield actuator and disposed between at least two of the first, second, or third RF coils, wherein the at least one magnetic field confinement shield covers one or more turns of the first, second, or third RF coil from at least one or more turns of another RF coil and is adjustable such that a coil-to-coil magnetic field produced when an RF current flows through the first, second, or third RF coils is adjustable and partially confined from at least one other of the first, second, or third RF coils;
a controller communicatively coupled to the coil actuator and the shield actuator such that coil-to-coil magnetic field coupling and coil-to-plasma magnetic field coupling is adjustable; and
wherein the plasma processing apparatus is configured such that, when RF current flows through the each of the RF coils, either the RF current flows out-of-phase through at least one of the first, second, or third RF coils with respect to at least another of the first, second, or third RF coils when the first RF coil is wound in a first direction and at least one of the second or third RF coils is wound in a second direction opposite the first direction or a phase of the RF current may be selectively controlled to be in-phase or out-of-phase in at least one of the first, second, or third RF coils with respect to at least another of the first, second, or third RF coils using a phase shifter coupled to at least one of the first, second, or third RF coils.

2. The plasma processing apparatus of claim 1 , wherein the at least one magnetic field confinement shield can be moved vertically to cover at least a portion of at least one of the first, second, or third RF coils.

3. The plasma processing apparatus of claim 1 , wherein the at least one magnetic field confinement shield is azimuthally asymmetric and can be moved rotationally to vary an orientation of the azimuthal asymmetry.

4. The plasma processing apparatus of claim 1 , wherein the at least one magnetic field confinement shield includes a separate magnetic field confinement shield for each one of the first, second, or third RF coils, and wherein each of the separate magnetic field confinement shields is independently movable and controllable.

5. The plasma processing apparatus of claim 1 , wherein the at least one magnetic field confinement shield only includes a first magnetic field confinement shield for the first RF coil and a second magnetic field confinement shield for the third RF coil, wherein each of the first and second magnetic field confinement shields is independently movable and controllable.

6. The plasma processing apparatus of claim 1 , wherein the at least one magnetic field confinement shield is a fixed ferrite wire coupled to a least a portion of at least one of the first, second or third RF coils.

7. The plasma processing apparatus of claim 1 , wherein the first, second, and third RF coils are movable in vertical and horizontal directions.

8. The plasma processing apparatus of claim 1 , wherein the at least one magnetic field confinement shield comprises a first plurality of vertical rods disposed adjacent to a given RF coil of the first, second, and third RF coils on a first side of the given RF coil and a second plurality of vertical rods disposed adjacent to the given RF coil on a second side of the given RF coil opposite the first side.

9. The plasma processing apparatus of claim 8 , wherein the first and second pluralities of vertical rods are arranged along an entire perimeter of the given RF coil.

10. The plasma processing apparatus of claim 8 , wherein the first and second pluralities of vertical rods are arranged along less than an entire perimeter of the given RF coil.

11. The plasma processing apparatus of claim 8 , wherein the first and second pluralities of vertical rods include at least a first individual vertical rod that is different than at least a second individual vertical rod in at least one of diameter, distance with respect to an adjacent vertical rod, distance with respect to the given RF coil, or magnetic permeability.

12. The plasma processing apparatus of claim 1 , wherein the first, second, and third RF coils are configured to rotate about a horizontal axis such that a first portion of the first, second, and third RF coils is disposed closer to the process chamber, and a second portion of the first, second, and third RF coil is disposed further from the process chamber.

13. The plasma processing apparatus of claim 1 , wherein the at least one magnetic field confinement shield is configured to move and cover at least a portion of at least one of the first, second or third RF coils to locally confine a magnetic field produced by an RF current flow through the first, second or third RF coils toward the process chamber.

14. The plasma processing apparatus of claim 1 , wherein the first, second, and third RF coils are configured to move in at least one of a vertical, horizontal, or rotational direction to control an intensity the magnetic field produced by an RF current flow through the first, second, or third RF coils.

Assignees

• Applied Materials Inc

Inventors

• Banna Samer
• Bishara Waheb
• Giar Ryan
• Todorow Valentin
• Lubomirsky Dmitry
• Tantiwong Kyle R

Classifications

• H05H2001/4667

  Electricity · mapped topic

• H05H1/46 Primary

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

• H05H1/4652

  using inductive coupling means, e.g. coils · CPC title

• H01J37/32183

  Matching circuits · CPC title

• H01J37/32174

  Circuits specially adapted for controlling the RF discharge · CPC title