Epitaxial growth of SiC with chlorinated precursors on different off-angle substrates

Abstract

This study focuses on the epitaxial growth of silicon carbide (SiC) epitaxial layers, adopting the chloride-based chemical-vapor-deposition (CVD) process, which allows to achieve ten times higher growth rate compared to the standard process based on the mixture of a silicon-containing gas and a hydrocarbon.In order to improve the material quality, substrates with different off-angles were used, since low off-angle substrates result in a reduction of killer defects for specific devices. Different growth mechanisms dominate for different substrate off-cut and an accurate set up of dedicated surface preparation procedures and tuning of growth parameters are needed. This study demonstrates that silicon-rich gas inputs are favorable for lower off-angle (nominally on-axis) substrates, while carbon-rich are beneficial for higher off-angles (usually 8° off-axis for 4H–SiC).Methyltrichlorosilane (MTS) is shown to be the best precursor to achieve the presented results.