Impurity incorporation kinetics during modified-Lely growth of SiC

The impurity incorporation kinetics during modified-Lely growth of silicon carbide (SiC) have been studied in terms of several growth parameters. It was found that the nitrogen incorporation is well described by a Langmuir isotherm type equation, implying that dynamic equilibrium between the vapor phase and the adsorbed nitrogen is established. The polytype of grown crystal and the seed orientation influence the impurity incorporation. For growth on (0001̄)C, 6H-SiC crystals always incorporate more nitrogen and less boron than 4H-SiC crystals, while no clear polytypic dependence of impurity incorporation is observed for growth on (11̄00) and (112̄0). Atomic force microscope observations revealed that there is a marked difference in the growth morphology between 6H-SiC(0001̄)C and 4H-SiC(0001̄)C. The origin of the polytypic dependence of impurity incorporation during growth on (0001̄)C is discussed with reference to the growth surface morphology.