Effect of post-deposition annealing temperature on CeO 2 thin film deposited on silicon substrate via RF magnetron sputtering technique

Abstract

Physical and electrical properties of CeO 2 thin film deposited on p-type silicon substrate via the RF magnetron sputtering technique after treating in argon ambient at different annealing temperatures has been investigated and reported. Thickness of the CeO 2 thin film was in the range of 30–40 nm measured by an ellipsometer at 5 different points for each sample. Post-deposition annealing was executed in argon ambient for 30 min at four different temperatures (400, 600, 800, and 1000 °C). The physical results demonstrated that the thin film was free of physical defects and root-mean square surface roughness decreased as the annealing temperature increased. X-ray diffraction indicated the occurrence of CeO 2 phase with four diffraction planes [(1 1 1), (2 0 0), (2 2 0), and (3 1 1)]. All samples showed negative flat band voltage shift owing to the existence of positive effective oxide charges. Samples annealed at 1000 °C showed the lowest interface trap density, total interface trap density, effective oxide charge, and the highest barrier height. This attributed to the lowest leakage current density (∼1×10 −9 A cm −2) and the highest electric breakdown voltage (∼30 V) of the sample when a comparison was made.