Patent ID: 11915912
Assignee: LAM RESEARCH CORPORATION
Field: Electrical machinery, apparatus, energy (Electrical engineering)
Classification: CPC H | IPC H

Claim 7:
8. A plasma system comprising:
a primary radio frequency (RF) generator configured to generate a primary RF signal;
a secondary RF generator configured to generate a secondary RF signal;
an impedance matching network coupled to the primary and secondary RF generators to receive the primary and secondary RF signals to output a modified RF signal, wherein the modified RF signal is output based on the primary and secondary RF signals;
a plasma chamber having an upper electrode coupled to the impedance matching network, wherein the upper electrode is configured to receive the modified RF signal to modify an impedance of plasma within the plasma chamber; and
a host computer coupled to the primary and secondary RF generators, wherein the host computer is configured to:
control the primary RF generator to pulse the primary RF signal in a first manner between a primary frequency level during a first time period and an off frequency level during a second time period;
control the secondary RF generator to pulse the secondary RF signal in a second manner between the off frequency level during the first time period and a secondary frequency level during the second time period;
control the primary RF generator to pulse the primary RF signal between the primary and off frequency levels during additional time periods in the same first manner as that during the first and second time periods; and
control the secondary RF generator to pulse the secondary RF signal between the off and secondary frequency levels during the additional time periods in the same second manner as that during the first and second time periods.