Patent ID: 9595424
Date: 2017-03-14
CPC Classifications: H01F,H01J,H03H

Claim:
1. An impedance matching circuit, comprising: a first circuit including a first plurality of tuning elements, the first circuit having an input coupled to a kilohertz (kHz) radio frequency (RF) generator; a second circuit having a second plurality of tuning elements, the second circuit having an input coupled to a low frequency megahertz (MHz) RF generator, the second plurality of tuning elements of the second circuit being arranged in an adjacent orientation to the first plurality of tuning elements of the first circuit; a third circuit having a third plurality of tuning elements, the third circuit having an input coupled to a high frequency MHz RF generator, the third plurality of tuning elements of the third circuit being arranged in an adjacent orientation to the second plurality of tuning elements of the second circuit; an output of the first, second, and third circuits coupled to an input of an RF transmission line, and an output of the RF transmission line is coupled to an electrode of a plasma chamber, wherein the first circuit and the second circuit provide isolation between a kHz RF signal reflected through the first circuit and a low frequency MHz RF signal reflected through the second circuit, wherein the isolation between the kHz RF signal reflected through the first circuit and the low frequency MHz RF signal reflected through the second circuit is provided by an increased number of tuning elements at an interface between the kHz and low frequency MHz RF signals as compared to an interface between the low frequency MHz RF signal and a high frequency MHz RF signal reflected through the third circuit, wherein the kHz RF signal reflected through the first circuit is a portion of an RF signal reflected from the plasma chamber via the RF transmission line towards the kHz RF generator, wherein the low frequency MHz RF signal reflected through the second circuit is another portion of the RF signal reflected from the plasma chamber via the RF transmission line towards the low frequency MHz RF generator.