ULTRA-THIN 3C-SIC PSEUDOMORPHIC FILMS ON SI(100) PREPARED BY ORGANOMETALLIC CVD WITH METHYLTRICHLOROSILANE

The large lattice mismatch and different thermal dilatation make the p seudomorphic growth of 3C-SiC on Si to appear impossible. Therefore ve ry thick films (greater than or equal to 20 mu m) have to be grown in order to relax the interface defects and obtain good quality heteroepi taxial films [H. Morkoc, S. Strite, G.B. Gao, M.E. Lin, B. Svertlov, M . Burns, J. Appl. Phys., 76 (1994 1363; S. Veprek, Th. Kunstmann, D. V olm, B. Meyer, J. Vac. Sci. Technol. A, 15 (1997) 10 (and references t herein)]. In the course of the study of the initial stages of the grow th using a UHV-compatible CVD apparatus and in-situ low energy electro n diffraction (LEED) we find that up to several nm thin films provide LEED patterns corresponding to a 3 X 2 reconstructed surface las docum ented in literature for 3C-SiC surfaces) and appear relatively homogen eous. Increasing the thickness upon longer deposition time leads to th e disappearance of this LEED pattern and to pronounced surface roughen ing. These results indicate that the novel organometallic CVD techniqu e [Veprek et al.] may open a way towards the preparation of a pseudomo rphic 3C-SiC films. (C) 1998 Eisevier Science S.A.