Growth behavior of cristobalite SiO2 coating on 4H–SiC surface via high-temperature oxidation

When SiO2 films undergo oxidation on 4H–SiC, a distinctive crystalline phase, cristobalite, emerges at elevated temperatures. We deeply explored the growth mechanism of the crystallite, focusing on its dependence on the silicon sublimation process (SSO). Activation energy calculations confirmed that the oxidation after SSO above 1350 °C exhibits a lower activation energy. The reduced activation energy suggests the elimination of the solid-phase diffusion process during oxidation. We devised a controllable growth process for the quartz phase to achieve a seamless transition from 0 to 100 % in the area proportion of cristobalite in SiO2. This strategic approach facilitates the precise preparation of oxide layers and holds potential applications in semiconductor device manufacturing.