Analyses of an Oriented Diamond Nucleation Processes on Si Substrate by Hot Filament Chemical Vapor Deposition

Abstract

Bias-enhanced nucleation (BEN) of oriented diamond on Si(100) substrates was investigated by ellipsometric monitoring using hot-filament chemical vapor deposition (HF-CVD). A plasma was observed above the substrate on the Mo holder by a glow discharge during the BEN process. We confirm that this plasma plays a critical role in the BEN process. A diamond film growth boundary was present when the initial bias voltage was below -250 V. The results of the ellipsometric monitoring indicate that the BEN process includes the following stages: carbonization, incubation, nucleation, nuclei growth and film growth. A scanning electron micrograph showed that biasing for too long induces twinned crystals. It is showed that the biasing time is a very important factor in oriented nucleation.