Conversion of single crystal Si(100) to SiC film by C₂H₂

Abstract

SiC thin films grown from the reaction between acetylene (C₂H₂) and the Si(100) substrates in a horizontal hot-wall CVD reactor by different procedures were studied using x-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). The growth of the SiC films was observed from the behavior of Si_2p peaks and their plasmons. A SiC thin film with a thickness of 35 Å and having a smooth surface morphology was obtained in C₂H₂ diluted by H₂ at 1050 °C for a period of 60 min. Etch pits and hillocks were observed with increasing reaction time at 1050 °C. For the conversion conducted in C₂H₂, but in the absence of H₂, a SiC monolayer with smooth morphology was obtained at 950 °C for 7 min and defects were observed for longer reaction times at this temperature. Defects were also observed for reaction times as short as 10 s at higher reaction temperatures (e.g., 1000 °C). H₂ seems to play a key role in suppressing the formation of defects and the reaction between C₂H₂ and Si substrate. The formation of defects was correlated to the out-diffusion of Si in the carbonization process.