US 12,217,972 B2
Multi-state pulsing for achieving a balance between bow control and mask selectivity
Nikhil Dole, Castro Valley, CA (US); Merrett Tinlok Wong, San Carlos, CA (US); Eric Hudson, Berkeley, CA (US); Sangheon Lee, South San Francisco, CA (US); and Xiaoqiang Yao, San Jose, CA (US)
Assigned to Lam Research Corporation, Fremont, CA (US)
Appl. No. 17/779,520
Filed by Lam Research Corporation, Fremont, CA (US)
PCT Filed Dec. 3, 2020, PCT No. PCT/US2020/063142
§ 371(c)(1), (2) Date May 24, 2022,
PCT Pub. No. WO2021/118862, PCT Pub. Date Jun. 17, 2021.
Claims priority of provisional application 62/961,358, filed on Jan. 15, 2020.
Claims priority of provisional application 62/948,180, filed on Dec. 13, 2019.
Prior Publication US 2023/0005717 A1, Jan. 5, 2023
Int. Cl. H01L 21/311 (2006.01); H01J 37/32 (2006.01); H01L 21/3065 (2006.01)
CPC H01L 21/31144 (2013.01) [H01J 37/32146 (2013.01); H01J 37/32165 (2013.01); H01J 37/32183 (2013.01); H01L 21/3065 (2013.01); H01L 21/31116 (2013.01); H01J 37/32174 (2013.01); H01J 2237/334 (2013.01); H01J 2237/3346 (2013.01)] 26 Claims
OG exemplary drawing
 
1. A method for multi-state pulsing to achieve a balance between bow control and mask selectivity, comprising:
generating a primary radio frequency (RF) signal, wherein the primary RF signal pulses among three states including a first state, a second state, and a third state;
generating a secondary RF signal, wherein the secondary RF signal pulses among the three states,
wherein during the first state, the primary RF signal has a power level that is greater than a power level of the secondary RF signal;
wherein during the second state, the secondary RF signal has a power level that is greater than a power level of the primary RF signal,
wherein during the third state, power levels of the primary and secondary RF signals are within a pre-determined range.