Epitaxial growth of SiC-heterostructures on alpha-SiC(0001) by solid-source MBE

Epitaxial growth of SiC on alpha-SiC(0001) has been performed by means of s olid-source molecular beam epitaxy (MBE). Low temperature (T < 1200 degrees C) deposition on on-axis SiC substrates always results in the growth of 3C -SiC, which is significantly improved by an alternating supply of Si and C. On vicinal substrates, a step flow growth mode has been realized at T down to 1050 degrees C. In experiments performed at T > 1200 degrees C, with a step decrease of supersaturation, a step-flow growth mode and for the first time nucleation of both 4H- and 6H-SiC under C-rich conditions was obtaine d. Based on these results we have demonstrated the growth of a double-heter ostructure by firstly growing a 3C-SiC film on 4H-SiC(0001) at low temperat ure and a subsequent growth of 4H-SiC at low supersaturation on a C-stabili zed surface on top of this film. Moreover, we also propose a new model to e xplain quantitatively the occurrence of different growth features and polyt ypes under certain growth conditions. (C) 1999 Elsevier Science S.A. All ri ghts reserved.