Apparatus and method for tuning electrode impedance for high frequency radio frequency and terminating low frequency radio frequency to ground

Embodiments of the present invention relate to apparatus for improving uniformity and film stress of films deposited during plasma process of a substrate. According to embodiments, the apparatus includes a tuning electrode and/or a tuning ring electrically coupled to a variable capacitor for tuning high frequency RF impedance of the electrode and a low frequency RF termination to ground. The plasma profile and resulting film thickness can be controlled by adjusting the capacitance of the variable capacitor and the resulting impedance of the tuning electrode. The film stress of the film deposited on the substrate can be controlled, i.e., increased, by terminating the low frequency RF during processing.