A THEORETICAL-STUDY OF THE INITIAL-STAGE OF DIAMOND FILM GROWTH ON SI(001) .1. ADSORPTION PROCESSES OF SOME HYDROCARBON FRAGMENTS

The adsorption processes of methyl CH3, ethylene C2H4 and acetylene C2H2 on Si(001)-2 X 1 surface have been studied theoretically by means of discrete variational X(alpha) methodtional X method. The possible adsorption positions of methyl CH3, acetylene C2H2 and ethylene C2H2 on Si(001)-2 x 1 were searched and the calculation results showed that the optimum adsorption position is the bridge site for the three hydrocarbon fragments. We also found that ethylene C2H2 easily converts to acetylene C2H2. The formation processes of C-3 species from methyl CH3 and acetylene C2H2 have been studied, and the two adsorption sites of the C-3 species, as well as a tilt angle of 9 degrees between the plane of the C-3 species and the Si(001) plane, are shown. Part of the experiments concerning diamond film growth with hot filament chemical vapor deposition were explained.