Abstract: A plasma chamber RF excitation system includes a high frequency RF power source having a fixed RF match circuit at its output and sensing and control apparatus for sensing the amount of RF power delivered by the RF power source and for regulating the output power level of the RF power source so as to maintain the RF power delivered by the RF power source at a desired level, and an RF plasma chamber including an RF radiator. The power source is mounted proximate or directly on the plasma chamber so that the distance between them is much less than an eighth of a wavelength at thr frequency of the RF source. The system may further include an endpoint detector for a plasma etch process or a chamber cleaning process which halts the process when the VSWR or reflected power ceases to change in response to the progress of the etch process.