High-quality 4H-SiC homoepitaxial layers grown by step-controlled epitaxy

Abstract
4H‐SiC bulk crystals were grown controllably by means of a modified Lely method. Homoepitaxial growth of 4H‐SiC was carried out by vapor phase epitaxy utilizing step‐controlled epitaxy on 4H‐SiC substrates prepared by the modified Lely method. The physical properties (electrical and optical properties) of 4H‐SiC epilayers were characterized by Hall effects and photoluminescence (PL) measurements. The electron mobilities as high as 720 cm2/V s at 292 K, and 11 000 cm2/V s at 77 K were obtained. In the PL measurement, the epilayers with a thickness more than 20 μm showed luminescence attributed to free exciton recombination, which indicates the improvement of crystal quality by step‐controlled epitaxy.