Patent ID: 11908660
Assignee: LAM RESEARCH CORPORATION
Field: Electrical machinery, apparatus, energy (Electrical engineering)
Classification: CPC H | IPC H

Claim 16:
17. A plasma system comprising:
a low frequency (LF) radio frequency (RF) generator configured to generate an LF RF signal;
a high frequency (HF) RF generator configured to generate an HF RF signal;
an impedance matching circuit coupled to the LF RF generator and the HF RF generator, wherein the impedance matching circuit is configured to receive the LF RF signal and the HF RF signal to output a modified signal;
a plasma chamber coupled to the impedance matching circuit to receive the modified signal; and
a controller coupled to the HF RF generator and the impedance matching circuit, wherein the controller is configured to:
determine a capacitance of the impedance matching circuit for which power reflected towards the HF RF generator is reduced;
determine a plurality of offsets from a reference frequency of the HF RF generator, wherein each of the plurality of offsets is determined for a corresponding one of a plurality of time intervals of a cycle of a waveform associated with the LF RF generator;
control the impedance matching circuit to have the capacitance; and
control the HF RF generator to operate at the plurality of offsets with respect to the reference frequency.