Atomic layer deposition of tin oxide with nitric oxide as an oxidant gas

Abstract

Atomic layer deposition (ALD) of tin oxide (SnO₂) thin films was achieved using a cyclic amide of Sn(II) (1,3-bis(1,1-dimethylethyl)-4,5-dimethyl-(4R,5R)-1,3,2-diazastannolidin-2-ylidene) as a tin precursor and nitric oxide (NO) as an oxidant gas. Film properties as a function of growth temperature from 130–250 °C were studied. Highly conducting SnO₂ films were obtained at 200–250 °C with the growth per cycle of ∼1.4 Å/cycle, while insulating films were grown at temperatures lower than 200 °C. Conformal growth of SnO₂ in holes of aspect-ratios up to ∼50 : 1 was successfully demonstrated.