SURFACE KINETICS OF ADATOMS IN VAPOR-PHASE EPITAXIAL-GROWTH OF SIC ON 6H-SIC(0001) VICINAL SURFACES

Growth of SiC on off-oriented 6H-SiC{0001} substrates was quantitatively analyzed based on the theory proposed by Burton, Cabrera, and Frank (BCF theory). By measuring the critical growth conditions where the growth mode changed from step-flow to two-dimensional nucleation, the surface diffusion lengths of adatoms on 6H-SiC(0001)Si and (000 $$($) over bar 1)C faces were calculated with the model. Although the nucleation rate was much higher on (000 $$($) over bar 1)C faces, the surface diffusion length was longer on (000 $$($) over bar 1)C faces. This brought about little difference in the step-flow growth condition on both faces. Growth conditions where step-flow growth takes place were predicted as a function of growth parameters such as temperature, growth rate, and off-angle of substrates. The analysis on off-angle dependence of growth rate revealed that desorption of adatoms was negligible and the condensation coefficient of supplied species onto the surface was almost unity on substrates with off-angles of more than 3 degrees.