Comparative Study of 4H-SiC Epitaxial Layers Grown on 4° Off-Axis Si- and C-Face Substrates Using Bistrimethylsilylmethane Precursor

Abstract

In situ H2 etching and homoepitaxial growth of 4H-SiC have been carried out on 4° off-axis Si-face and C-face substrates by low-pressure chemical vapor deposition. We systematically analyzed H2 etching characteristics and epitaxial growth of 4H-SiC substrates on two different polarities using an organosilicon source material, bistrimethylsilylmethane (C7H20Si2). The effects of the growth conditions, such as growth temperature and source flow rate on the surface morphology, crystallinity, polytype conversion, defect generation, and structural imperfection of the epilayers on different polar surfaces, were investigated. High-quality epitaxial layers were successfully grown at low temperature range of 1320–1440°C on the Si-face and 1500°C on the C-face. A low source flow rate of 5–10 sccm was also preferred to grow defect-free epilayers.