Influence of substrate surface morphology on growth CaF2 on Si (100) in low and high temperature modes

The growth of CaF₂ on Si (100) substrates of various qualities was studied for low and high temperature modes at an early growth stages. The growth of samples was carried out by MBE at growth temperature about ~5000°C (low temperature mode) and about ~7500°C (high temperature mode).. The surface morphology of the substrates and the grown structures was studied in semi contact mode with an ambient air Solver P47H NT-MDT atomic force microscope. It was found, that depending on the substrate surface morphology, either triangular shaped CaF₂ islands are formed on Si (100) or rectangular shaped CaF₂ islands are developed, leaving the most part of a substrate surface uncovered, for low temperature mode. While in high temperature mode on the both types of substrate rectangular shaped CaF₂ islands are formed, covering the substrate almost uniformly. In low temperature mode a substrate surface morphology strongly influences morphology of CaF₂ films defining formation of structure defects at an initial growth stage.