Near-equilibrium growth of micropipe-free 6H-SiC single crystals by physical vapor transport

A process for growing micropipe-free single crystals has been developed by using the modified Lely method, The process parameters were: kept dose to thermal equilibrium. The maximum average thermal gradient inside the growth furnace leading to micropipe-free growth was 5 K/cm., A gradient of 7.5 K/cm already resulted in a strong defect formation and produced a high density of micropipes (>200cm(-2)). The highest achieved growth rate providing micropipe-free growth was 0.27 mm/h. For the employed parameter range, 6H-SiC single boule crystals were grown on both the C face and the Si face of 6H-SiC Lely platelets, The grown crystals :were electrically and optically characterized. (C) 1998 American Institute of Physics.