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

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.