High-purity and thick 4H-and 6H-SiC(0001) epitaxial growth by cold-wall chemical vapor deposition and high-voltage pin diodes

Thick (> 30 mum) 4H- and 6H-SiC(0001) epilayers have been grown by cold-wal l chemical vapor deposition. The increased thickness of a polycrystalline S iC film coated on a graphite susceptor has allowed growth time to be prolon ged, enabling thick epitaxy in one growth ran. The unintentionally doped ep ilayers grown with a C/Si ratio of 2 show low net donor concentrations of 2 similar to 5 x 10(14) cm(-3), In low-temperature photoluminescence, very s trong free-exciton peaks have been observed, indicating the high purity of the epilayers. A high breakdown voltage of 4200 V has been achieved for a 6 H-SiC epitaxial pin diode with a thickness of 31 mum.