Methods and apparatus for symmetrical hollow cathode electrode and discharge mode for remote plasma processes

Patent metadata

Field	Value
Publication number	US-2021384011-A1
Application number	US-202016894002-A
Country	US
Kind code	A1
Filing date	Jun 5, 2020
Priority date	Jun 5, 2020
Publication date	Dec 9, 2021
Grant date	—

Abstract

Methods and apparatus for reducing particle generation in a remote plasma source (RPS) include an RPS having a first plasma source with a first electrode and a second electrode, wherein the first electrode and the second electrode are symmetrical with hollow cavities configured to induce a hollow cathode effect within the hollow cavities, and wherein the RPS provides radicals or ions into the processing volume, and a radio frequency (RF) power source configured to provide a symmetrical driving waveform on the first electrode and the second electrode to produce an anodic cycle and a cathodic cycle of the RPS, wherein the anodic cycle and the cathodic cycle operate in a hollow cathode effect mode.

First claim

1 . An apparatus for processing a substrate, comprising:
a process chamber with a chamber body enclosing a processing volume; a remote plasma source (RPS) having a first plasma source with a first electrode and a second electrode, wherein the first electrode and the second electrode are symmetrical with hollow cavities configured to induce a hollow cathode effect within the hollow cavities, and wherein the RPS is configured to provide radicals or ions into the processing volume; and a radio frequency (RF) power source configured to provide a symmetrical driving waveform on the first electrode and the second electrode to produce an anodic cycle and a cathodic cycle of the RPS, wherein the anodic cycle and the cathodic cycle operate in a hollow cathode effect mode.

2 . The apparatus of claim 1 , wherein the symmetrical driving waveform is a sinusoidal waveform or a square wave waveform.

3 . The apparatus of claim 1 , further comprising:
an isolator between the first electrode and the second electrode.

4 . The apparatus of claim 3 , wherein the isolator has a ring shape.

5 . The apparatus of claim 4 , wherein the isolator has at least one groove on a radially inward side of the ring shape that is configured to be exposed to generated plasma from the first electrode and the second electrode.

6 . The apparatus of claim 3 , wherein the isolator is formed of a ceramic material.

7 . The apparatus of claim 1 , wherein the first electrode and the second electrode have hollow cavities with a cone shape having a first end with a first diameter opening and a second end with a second diameter opening, wherein the second diameter opening is larger than the first diameter opening.

8 . The apparatus of claim 7 , wherein the second diameter opening of the first electrode is configured to face the second diameter opening of the second electrode.

9 . The apparatus of claim 1 , further comprising:
a mixing reservoir located between the first plasma source and the processing volume.

10 . The apparatus of claim 1 , further comprising:
a second plasma source with a third electrode and a fourth electrode, wherein the third electrode and the fourth electrode are symmetrical with hollow cavities configured to induce a hollow cathode effect within the hollow cavities.

11 . The apparatus of claim 10 , wherein the first plasma source and the second plasma source provide radicals or ions into a mixing reservoir that is fluidly connected to the processing volume.

12 . An apparatus for processing a substrate, comprising:
a remote plasma source (RPS) having a first plasma source with a first electrode and a second electrode, wherein the first electrode and the second electrode are symmetrical with hollow cavities configured to induce a hollow cathode effect within the hollow cavities; and a radio frequency (RF) power source configured to provide a symmetrical driving waveform on the first electrode and the second electrode to produce an anodic cycle and a cathodic cycle of the RPS, wherein the anodic cycle and the cathodic cycle operate in a hollow cathode effect mode.

13 . The apparatus of claim 12 , wherein symmetrical driving waveform is a sinusoidal waveform or a square wave waveform.

14 . The apparatus of claim 12 , further comprising:
an isolator between the first electrode and the second electrode, wherein the isolator has a ring shape and is formed of a ceramic based material, and wherein the isolator has at least one groove on a radially inward side of the ring shape that is configured to be exposed to generated plasma from the first electrode and the second electrode.

15 . The apparatus of claim 12 , wherein the first electrode and the second electrode have hollow cavities with a cone shape having a first end with a first diameter opening and a second end with a second diameter opening, wherein the second diameter opening is larger than the first diameter opening.

16 . The apparatus of claim 15 , wherein the second diameter opening of the first electrode is configured to face the second diameter opening of the second electrode.

17 . The apparatus of claim 12 , further comprising:
a second plasma source with a third electrode and a fourth electrode, wherein the third electrode and the fourth electrode are symmetrical with hollow cavities configured to induce a hollow cathode effect within the hollow cavities, and wherein the first plasma source and the second plasma source provide radicals or ions into a mixing reservoir that is fluidly connected to a processing volume of a process chamber.

18 . A method of generating remote plasma for a process chamber, comprising:
generating a symmetrical driving waveform with a radio frequency (RF) power source for a first plasma source; and forming plasma in the first plasma source by applying the symmetrical driving waveform to a first electrode and to a second electrode of the first plasma source, wherein the first electrode and the second electrode are symmetrical with hollow cavities configured to induce a hollow cathode effect within the hollow cavities when driven by the symmetrical driving waveform.

19 . The method of claim 18 , further comprising:
forming plasma in a second plasma source by applying the symmetrical driving waveform to a third electrode and to a fourth electrode of the second plasma source, wherein the third electrode and the fourth electrode are symmetrical with hollow cavities configured to induce a hollow cathode effect within the hollow cavities when driven by the symmetrical driving waveform.

20 . The method of claim 19 , further comprising:
mixing radicals or ions generated by the first plasma source and the second plasma source in a mixing reservoir that is fluidly coupled to a processing volume of a process chamber.

Assignees

• Applied Materials Inc

Inventors

• Cho Tae Seung
• Natarajan Saravana Kumar
• Schatz Kenneth D
• Lubomirsky Dmitry
• Subramanya Samartha

Classifications

• H01J37/32596 Primary

  Hollow cathodes · CPC title

• H01J37/32357 Primary

  Generation remote from the workpiece, e.g. down-stream · CPC title

• H01J37/32128 Primary

  using particular waveforms, e.g. polarised waves · CPC title

• H05H1/46

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