Polytype formation in sublimation epitaxy of SiC on low off-axis substrates.

Abstract: Sublimation epitaxy of SiC on low off-axis substrates was performed. The growth was performed at different temperatures, mainly under vacuum conditions or with an initial atmosphere of N2 at 0.5 mbar (RT). Some additional experiments under different conditions (Ar background, higher temperature, higher off-axis substrate) were performed in order to further investigate growth influencing factors. The samples were characterized by optical microscopy and atomic force microscopy. A dependence of 3C/6H growth on substrate off-axis, as well as on temperature, was clear to be seen. Favored growth of 6H in the presence of N2 was found.  An enlargement effect on the 3C domains grown in N2 ambient was observed. Additionally a correlation between step bunching and growth rate was found in step flow growth on low off-axis substrates. Suggestions for relevant growth mechanisms are made. Further work is discussed.