Effects of post-deposition annealing temperature on metal-organic decomposed lanthanum cerium oxide film as metal reactive oxide layer on 4H-SiC

Abstract

Investigation of metal-organic decomposed LaxCeyOz film was performed on n-type 4H-SiC substrate by varying post-deposition annealing (PDA) temperature from 400 to 1000 °C. The LaxCeyOz acting as a metal reactive oxide layer was demonstrated, explained, and justified via X-ray photoelectron spectroscopy (XPS) through its effect in performing catalytic oxidation of the substrate with temperature as low as 400 °C and the removal of excess carbon, originated from the substrate itself, accumulated at the oxide/4H-SiC interface via formation of CO. Williamson–Hall approach has revealed an increment in crystallite size for LaxCeyOz with decreasing microstrains as PDA temperature increased. High resolution transmission electron microscopy showed the formation of a distinct amorphous interfacial layer in between the bulk oxide and SiC substrate. XPS analysis proved that the bulk oxide with a mixture of amorphous and crystalline regions was comprised of an intermixing of La, Ce, O, C, and La, Ce, O, Si, C elements while interfacial layer consisted of La, Ce, O, Si, and C elements.