Process stability and morphology optimization of very thick 4H–SiC epitaxial layers grown by chloride-based CVD

Abstract

The development of a chemical vapor deposition (CVD) process for very thick silicon carbide (SiC) epitaxial layers suitable for high power devices is demonstrated by epitaxial growth of 200µm thick, low doped 4H–SiC layers with excellent morphology at growth rates exceeding 100µm/h. The process development was done in a hot wall CVD reactor without rotation using both SiCl4 and SiH4+HCl precursor approaches to chloride based growth chemistry. A C/Si ratio <1 and an optimized in-situ etch are shown to be the key parameters to achieve 200µm thick, low doped epitaxial layers with excellent morphology.