IMPURITY INCORPORATION KINETICS DURING MODIFIED-LELY GROWTH OF SIC

The impurity incorporation kinetics during modified-Lely growth of sil icon carbide (SiC) have been studied in terms of several growth parame ters. It was found that the nitrogen incorporation is well described b y 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 impu rity incorporation. For growth on (000 (1) over bar)C, 6H-SiC crystals always incorporate more nitrogen and less boron than 4H-SiC crystals, while no clear polytypic dependence of impurity incorporation is obse rved for growth on (1 (1) over bar 00) and (11 (2) over bar 0). Atomic force microscope observations revealed that there is a marked differe nce in the growth morphology between 6H-SiC(000 (1) over bar)C and 4H- SiC(000 (1) over bar)C. The origin of the polytypic dependence of impu rity incorporation during growth on (000 (1) over bar)C is discussed w ith reference to the growth surface morphology. (C) 1998 American Inst itute of Physics.