US 11,901,161 B2
Methods and apparatus for symmetrical hollow cathode electrode and discharge mode for remote plasma processes
Tae Seung Cho, San Jose, CA (US); Saravana Kumar Natarajan, Tamil Nadu (IN); Kenneth D. Schatz, Los Altos, CA (US); Dmitry Lubomirsky, Cupertino, CA (US); and Samartha Subramanya, Bangalore (IN)
Assigned to APPLIED MATERIALS, INC., Santa Clara, CA (US)
Filed by APPLIED MATERIALS, INC., Santa Clara, CA (US)
Filed on May 26, 2022, as Appl. No. 17/824,977.
Application 17/824,977 is a continuation of application No. 16/894,002, filed on Jun. 5, 2020, granted, now 11,373,845.
Prior Publication US 2022/0293396 A1, Sep. 15, 2022
This patent is subject to a terminal disclaimer.
Int. Cl. H01J 37/32 (2006.01); H05H 1/46 (2006.01)
CPC H01J 37/32357 (2013.01) [H01J 37/32128 (2013.01); H01J 37/32596 (2013.01); H05H 1/46 (2013.01)] 20 Claims
OG exemplary drawing
 
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 formed of or coated with a nickel-based material and are symmetrical with hollow cavities having opposing cone shapes with a largest opening of each of the hollow cavities opposing each other, wherein the first electrode and the second electrode are configured to induce a hollow cathode effect within the hollow cavities, wherein the first electrode and the second electrode have parallel surfaces opposing each other that surround the largest opening of each of the hollow cavities and are separated by a gap, wherein the first electrode and the second electrode are at least partially coated with a ceramic material that is configured to reduce sputtering between the parallel surfaces during generation of plasma in the RPS, and wherein the RPS is configured to provide radicals or ions into the processing volume;
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; and
an isolator with a ring shape positioned between the first electrode and the second electrode and configured to reduce electric fields between the first electrode and the second electrode during generation of plasma in the RPS.