Apparatus for generating etchants for remote plasma processes

Patent metadata

Field	Value
Publication number	US-12002659-B2
Application number	US-202217869987-A
Country	US
Kind code	B2
Filing date	Jul 21, 2022
Priority date	Jun 13, 2022
Publication date	Jun 4, 2024
Grant date	Jun 4, 2024

Abstract

A remote plasma source (RPS) for generating etchants leverages symmetrical hallow cathode cavities to increase etchant rates. The RPS includes an upper electrode with a first hollow cavity configured to induce a hollow cathode effect within the first hollow cavity, a lower electrode with a second hollow cavity configured to induce a hollow cathode effect within the second hollow cavity, wherein the first hollow cavity and the second hollow cavity are symmetrical, a first gap positioned between and electrically separating the upper electrode and the lower electrode, and an annular dielectric cover in direct contact with the lower electrode in the first gap and forms a second gap between an uppermost surface of the annular dielectric cover and a lowermost surface of the upper electrode. The annular dielectric cover fills approximately 50% to approximately 95% of a height of the first gap.

First claim

The invention claimed is:

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 plasma source with an upper electrode and a lower electrode, wherein the upper electrode and the lower electrode are symmetrical with hollow cavities configured to induce a hollow cathode effect within the hollow cavities, wherein the upper electrode and the lower electrode are electrically separated by a first gap with an annular dielectric cover positioned within the first gap, wherein the annular dielectric cover is in direct contact with the lower electrode and forms a second gap between an uppermost surface of the annular dielectric cover and a lowermost surface of the upper electrode, wherein the annular dielectric cover fills approximately 50% to approximately 95% of a height of the first gap, 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 upper electrode and the lower 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 annular dielectric cover is a ceramic material.

3. The apparatus of claim 1 , wherein the annular dielectric cover has an outermost edge with a first thickness and an innermost edge with a second thickness less than the first thickness.

4. The apparatus of claim 3 , wherein the second thickness is approximately 1 millimeter to approximately 2 millimeters and the first thickness is less than approximately 95% of the height of the first gap.

5. The apparatus of claim 3 , wherein the first thickness slopes downward into a third thickness equal to the second thickness before reaching the innermost edge.

6. The apparatus of claim 1 , wherein the annular dielectric cover has an inner diameter greater than an outer edge of an opening of the hollow cavities.

7. The apparatus of claim 1 , wherein the annular dielectric cover has an inner diameter smaller than an outer edge of an opening of the hollow cavities and wherein an innermost edge of the annular dielectric cover extends, at least partially, into the opening.

8. The apparatus of claim 7 , wherein capillary holes are spaced in proximity of the innermost edge of the annular dielectric cover.

9. The apparatus of claim 8 , wherein the capillary holes have a diameter of less than two times a thickness of a sheath of plasma to be generated with the RPS.

10. The apparatus of claim 1 , wherein the upper electrode and the lower electrode are plated with electroless nickel plating.

11. The apparatus of claim 10 , wherein an yttria coating is applied to plasma exposed surfaces of the upper electrode and the lower electrode.

12. The apparatus of claim 10 , wherein an yttria coating is applied to plasma exposed surfaces with the first gap and in proximity of openings of the hollow cavities of the upper electrode and the lower electrode.

13. An apparatus for processing a substrate, comprising:
a remote plasma source (RPS) having a plasma source with an upper electrode and a lower electrode, wherein the upper electrode and the lower electrode are symmetrical with hollow cavities configured to induce a hollow cathode effect within the hollow cavities, wherein the upper electrode and the lower electrode are electrically separated by a first gap with an annular dielectric cover positioned within the first gap, wherein the annular dielectric cover is in direct contact with the lower electrode and forms a second gap between an uppermost surface of the annular dielectric cover and a lowermost surface of the upper electrode, wherein the annular dielectric cover fills approximately 50% to approximately 95% of a height of the first gap, and wherein the RPS is configured to provide radicals or ions; and
a radio frequency (RF) power source configured to provide a symmetrical driving waveform on the upper electrode and the lower 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.

14. The apparatus of claim 13 , wherein the annular dielectric cover has an outermost edge with a first thickness and an innermost edge with a second thickness less than the first thickness and wherein the second thickness is approximately 1 millimeter to approximately 2 millimeters and the first thickness is less than approximately 95% of the height of the first gap.

15. The apparatus of claim 14 , wherein the first thickness slopes downward into a third thickness equal to the second thickness before reaching the innermost edge.

16. The apparatus of claim 13 , wherein the annular dielectric cover has an inner diameter greater than an outer edge of an opening of the hollow cavities or wherein the annular dielectric cover has an inner diameter smaller than an outer edge of an opening of the hollow cavities and wherein an innermost edge of the annular dielectric cover extends, at least partially, into the opening.

17. The apparatus of claim 16 , wherein capillary holes are spaced in proximity of the innermost edge of the annular dielectric cover and wherein the capillary holes have a diameter of less than two times a thickness of a sheath of plasma to be generated with the RPS.

18. The apparatus of claim 13 , wherein the upper electrode and the lower electrode are plated with electroless nickel plating and wherein an yttria coating is applied to plasma exposed surfaces of the upper electrode and the lower electrode on the electroless nickel plating.

19. An apparatus for providing a remote plasma source (RPS) for generating etchants, comprising:
an upper electrode with a first hollow cavity configured to induce a hollow cathode effect within the first hollow cavity;
a lower electrode with a second hollow cavity configured to induce a hollow cathode effect within the second hollow cavity, wherein the first hollow cavity and the second hollow cavity are symmetrical;
a first gap positioned between and electrically separating the upper electrode and the lower electrode; and
an annular dielectric cover in direct contact with the lower electrode in the first gap and forms a second gap between an uppermost surface of the annular dielectric cover and a lowermost surface of the upper electrode, wherein the annular dielectric cover fills approximately 50% to approximately 95% of a height of the first gap, wherein the annular dielectric cover has an inner diameter smaller than an outer edge of an opening of the second hollow cavity which extends, at least partially, into the opening while directly in contact with a surface of the second hollow cavity, and wherein capillary holes are spaced in proximity of an innermost edge of the annular dielectric cover and have a diameter of less than two times a thickness of a sheath of plasma to be generated with the RPS.

20. The apparatus of claim 19 , wherein the upper electrode and the lower electrode are plated with electroless nickel plating and an yttria coating is applied to plasma exposed surfaces of the upper electrode and the lower electrode over the electroless nickel plating.

Assignees

• Applied Materials Inc

Inventors

• Cho Tae Seung
• Benjaminson David Michael
• Schatz Kenneth
• Pakulski Ryan Michael
• Choy Martin Yue
• Gunaseelan Pratheep
• Huang Chih-Yung

Classifications

• H01J37/32091

  the radio frequency energy being capacitively coupled to the plasma · CPC title

• H01J37/3244

  Gas supply means · CPC title

• H01J37/32596 Primary

  Hollow cathodes · CPC title

• H01J37/32541

  Shape · CPC title

• H01J37/32568

  Relative arrangement or disposition of electrodes; moving means · CPC title