US 12,482,634 B2
Symmetric coupling of coil to direct-drive radiofrequency power supplies
John Drewery, San Jose, CA (US); and Alexander Miller Paterson, San Jose, CA (US)
Assigned to Lam Research Corporation, Fremont, CA (US)
Appl. No. 18/689,030
Filed by Lam Research Corporation, Fremont, CA (US)
PCT Filed Sep. 14, 2022, PCT No. PCT/US2022/043464
§ 371(c)(1), (2) Date Mar. 4, 2024,
PCT Pub. No. WO2023/043795, PCT Pub. Date Mar. 23, 2023.
Claims priority of provisional application 63/245,773, filed on Sep. 17, 2021.
Prior Publication US 2024/0395503 A1, Nov. 28, 2024
Int. Cl. H01J 37/32 (2006.01)
CPC H01J 37/32165 (2013.01) [H01J 37/32128 (2013.01); H01J 37/32146 (2013.01); H01J 37/32183 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A plasma processing system, comprising:
a plasma processing chamber;
a coil disposed next to the plasma processing chamber, the coil having a first end and a second end;
a first direct-drive radiofrequency power supply having an output through which a first shaped-amplified square waveform signal is transmitted;
a first reactive circuit connected between the output of the first direct-drive radiofrequency power supply and the first end of the coil, the first reactive circuit configured to transform the first shaped-amplified square waveform signal into a first shaped-sinusoidal signal in route to the first end of the coil;
a second direct-drive radiofrequency power supply having an output through which a second shaped-amplified square waveform signal is transmitted; and
a second reactive circuit connected between the output of the second direct-drive radiofrequency power supply and the second end of the coil, the second reactive circuit configured to transform the second shaped-amplified square waveform signal into a second shaped-sinusoidal signal in route to the second end of the coil.