RF IMPEDANCE MATCHING NETWORK

摘要

In one embodiment, an RF impedance matching network includes an RF input configured to operably couple to an RF source; an RF output configured to operably couple to a plasma chamber; a first electronically variable capacitor having a first variable capacitance; a second electronically variable capacitor having a second variable capacitance; and a control circuit operably coupled to the first and second electronically variable capacitors. The control circuit is configured to determine the variable impedance of the plasma chamber, determine a first capacitance value for the first variable capacitance and a second capacitance value for the second variable capacitance, and generate a control signal to alter the first and/or second variable capacitance. An elapsed time between determining the variable impedance of the plasma chamber to when RF power reflected back to the RF source decreases is less than about 150 μsec.

主权项

1. A radio frequency (RF) impedance matching network comprising:
an RF input configured to operably couple to an RF source; an RF output configured to operably couple to a plasma chamber having a variable impedance; a first electronically variable capacitor having a first variable capacitance; a second electronically variable capacitor having a second variable capacitance; and a control circuit operably coupled to the first electronically variable capacitor and to the second electronically variable capacitor to control the first variable capacitance and the second variable capacitance, wherein the control circuit is configured to:
determine the variable impedance of the plasma chamber;determine a first capacitance value for the first variable capacitance and a second capacitance value for the second variable capacitance; andgenerate a control signal to alter at least one of the first variable capacitance and the second variable capacitance to the first capacitance value and the second capacitance value, respectively;wherein an elapsed time between determining the variable impedance of the plasma chamber to when RF power reflected back to the RF source decreases is less than about 150 μsec.