High-rate deposition of Ta-doped SnO2 films by reactive magnetron sputtering using a Sn–Ta metal-sintered target

Abstract Ta-doped SnO 2 films were deposited on glass substrate (either unheated or heated at 200 °C) by reactive magnetron sputtering with a Sn–Ta metal-sintered target using a plasma control unit (PCU) and mid-frequency (mf, 50 kHz) unipolar pulsing. The PCU feedback system precisely controlled the flow of the reactive and sputtering gases (O 2 and Ar, respectively) by monitoring either discharge impedance or the plasma emission of the atomic O* line at 777 nm. The planar target was connected to the switching unit, which was operated in unipolar pulse mode. Power density on the target was maintained at 4.4 W cm − 2 during deposition. The lowest obtained resistivity for the films deposited on heated substrate was 6.4 × 10 − 3  Ωcm, where the deposition rate was 250 nm min − 1 .