US 12,255,052 B2
Process control for ion energy delivery using multiple generators and phase control
Ranadeep Bhowmick, San Jose, CA (US); Felix Kozakevich, Sunnyvale, CA (US); Alexei Marakhtanov, Albany, CA (US); John Holland, Fremont, CA (US); and Eric Hudson, Fremont, CA (US)
Assigned to Lam Research Corporation, Fremont, CA (US)
Appl. No. 18/010,204
Filed by Lam Research Corporation, Fremont, CA (US)
PCT Filed Jul. 6, 2021, PCT No. PCT/US2021/040480
§ 371(c)(1), (2) Date Dec. 13, 2022,
PCT Pub. No. WO2022/010875, PCT Pub. Date Jan. 13, 2022.
Claims priority of provisional application 63/049,532, filed on Jul. 8, 2020.
Prior Publication US 2023/0230804 A1, Jul. 20, 2023
Int. Cl. H01J 37/32 (2006.01)
CPC H01J 37/32165 (2013.01) [H01J 37/32128 (2013.01); H01J 37/32183 (2013.01); H01J 2237/3343 (2013.01)] 19 Claims
OG exemplary drawing
 
1. A method for applying RF power in a plasma process chamber, comprising:
generating a first RF signal;
generating a second RF signal;
generating a third RF signal;
wherein the first, second, and third RF signals are generated at different frequencies;
combining the first, second and third RF signals to generate a combined RF signal, wherein a wave shape of the combined RF signal is configured to approximate a sloped square wave shape;
applying the combined RF signal to a chuck in the plasma process chamber;
wherein the wave shape of the combined RF signal is configured to compensate for a capacitance of the chuck, so that the combined RF signal that reaches a wafer supported by the chuck has a wave shape that approximates a non-sloped square wave shape.