Initial Stages of Growth of Barium Zirconate Titanate and Barium Stannate Titanate Films on Single-Crystal Sapphire and Silicon Carbide

Abstract

The initial stages of growth of barium zirconate titanate and barium stannate titanate ferroelectric films on single-crystal sapphire and silicon carbide are studied for the first time. The choice of substrates is dictated by the possibility of using such structures in ultra-high frequency devices. The growth of discontinuous BaZrxTi1–xO3 films is found to be mediated by the gas phase mass transport mechanism in the studied temperature range. For deposition of BaSnxTi1–xO3 films, the mechanism of mass transport switches at ~800°C from surface diffusion to gas phase diffusion; also, the films deposited on sapphire and silicon carbide have considerably different elemental composition. The formation of an intermediate SiO2 layer is noted on silicon carbide during the growth of oxide films on this substrate, its thickness depending on the deposition temperature.