High-rate deposition of Ta-doped SnO_2 films by reactive magnetron sputtering using a Sn-Ta metal-sintered target

摘要

Ta-doped SnO_2 films were deposited on glass substrate (either unheated or heated at 200 ℃) 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).