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

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 200 µm thick, low doped 4H-SiC layers with excellent morphology at growth rates exceeding 100 µm/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 200 µm thick, low doped epitaxial layers with excellent morphology.