Ion energy measurement at the powered electrode in an rf discharge

Abstract

Ion energy measurements have been performed with an electrostatic parallel plate energy analyzer at the powered electrode of a 13.56–MHz rf discharge. Considerable splitting of the ion energy distributions is observed due to rf oscillations. Plasma potential, sheath thickness, and total ion current are derived from the observed energy profiles. Low-pressure operation of the plasma at several mTorr permits a collisionless sheath approximation and gives rise to well-defined energy spectra.