Systems and methods for extracting process control information from radiofrequency supply system of plasma processing system

A radiofrequency signal generator system for a plasma processing system, comprising:

• a first radiofrequency signal generator set to generate a low frequency signal at an output of the first radiofrequency signal generator;
• a second radiofrequency signal generator set to generate a high frequency signal at an output of the second radiofrequency signal generator;
• an impedance matching system having a first input connected to the output of the first radiofrequency signal generator and a second input connected to the output of the second radiofrequency signal generator, the impedance matching system having an output connected to a radiofrequency supply input of the plasma processing system, the impedance matching system configured to control impedances at the output of the first radiofrequency signal generator and at the output of the second radiofrequency signal generator;
• and
• a control module programmed to:
• monitor a reflected voltage at the output of the second radiofrequency signal generator, and
• determine when the reflected voltage at the output of the second radiofrequency signal generator indicates a change in impedance along a transmission path of the high frequency signal, wherein the change is indicative of a corresponding process condition and/or event within the plasma processing system.