AC Plasma-Assisted Chemical Vapor Deposition of Cubic Silicon Carbide on Silicon Substrate

Abstract

Cubic SiC films were deposited on Si substrates by AC plasma-assisted chemical vapor deposition (CVD) using SiH₄ and CH₄ as source materials at a substrate temperature of 750 °C-1150°C. When the ratio of SiH₄ to CH₄ (Si/C) increases, the structures of films changed from amorphous to polycrystalline loaded with excess Si at a low substrate temperature less than 1000° C, reflecting a Si radical steeply increases and a H radical is saturated. Excess Si in the SiC films disappeared by applying a substrate bias, suggesting H radicals excited by electrons extract excess Si from the films. The plasma assists the dissociation of source materials and the cleaning effects of the growing surfaces by reactive species. The substrate bias enhances the surface reactions and crystallization.