STUDY OF A RF PLANAR MAGNETRON SPUTTERING DISCHARGE - DISCHARGE CHARACTERISTICS AND PLASMA DIAGNOSTICS

Electrical and Langmuir probe measurements and energy analysis of the ions impinging on the substrate electrode were used to characterize a rf planar magnetron sputtering discharge. The pressure range examined was 0.26-5.33 Pa in both argon and argon-nitrogen mixtures. The electrical measurements allowed us to determine the rf target voltage V(rf) and the self-bias target voltage V(dc) as a function of rf input power, process pressure and dc substrate bias voltage. The electron density n(e), the electron temperature T(e) and the mean plasma potential V(p)BAR were measured using Langmuir probe diagnostics. These time-averaged plasma parameters were investigated as a function of rf input power, process pressure and dc substrate bias voltage. An energy electrostatic analyser was used to study the energy of ions impinging on the negatively biased substrate electrode. The energy distributions depended on the voltage drop across the substrate sheath and on the collisions in the sheath. They were broadened by the rf modulation.