Patent ID: 8144329

Claim:
A method for controlling a plasma in a substrate processing system, comprising: controlling a first set of wavelength intensities of reflected electromagnetic radiation reflected from the plasma within a chamber before processing a first set of one or more substrates; associating the first set of wavelength intensities of reflected electromagnetic radiation to an RF power within the processing system; adjusting a matching circuit based on the first set of wavelength intensities of reflected electromagnetic radiation; processing the first set of one or more substrates in the substrate processing system; controlling a second set of wavelength intensities of reflected electromagnetic radiation reflected from the plasma within the chamber; associating the second set of wavelength intensities of reflected electromagnetic radiation to the RF power within the processing system; and adjusting the matching circuit based on the first or the second set of wavelength intensities of reflected electromagnetic radiation, while processing a second set of one or more substrates of a different type than the first set of one or more substrates.