Abstract
Al2O3 films deposited on 4H-SiC(0001) by atomic layer deposition (ALD) were characterized by x-ray photoelectron spectroscopy (XPS), and high resolution transmission electron microscopy (HRTEM). The effect of medium and high temperature (873, 1273 K) annealing on samples with oxide thicknesses of 5-8nm and 100-120nm was studied. XPS indicated presence of a thin (~1nm) SiOx layer on the as-grown samples which increased to ~3 nm after annealing above crystallization temperature (1273 K) in Ar atmosphere. Upon annealing the stoichiometry of the interfacial oxide approaches that of SiO2. HRTEM showed that the thickness of the interfacial oxide formed after annealing at 1273 K was not uniform. No significant increase in the thickness of the interfacial oxide, was observed after annealing at 873 K in a N2 (90%) / H2 (10%) atmosphere.