Reaction intermediate in thermal decomposition of 1,3-disilabutane to silicon carbide on Si(111) Comparative study of Cs+ reactive ion scattering and secondary ion mass spectrometry

1,3-Disilabutane (CH3SiH2CH2SiH3; DSB) is a single-source precursor for chemical vapor deposition of a silicon carbide film. We investigate the intermediate species involved in the decomposition of DSB on Si(111) for the temperature range 150-1100 K by Cs+ reactive ion scattering (RIS) and low-energy secondary ion mass spectrometry (SIMS) techniques. C2H8Si2 and CH4Si are identified as molecular intermediates present at 150-270 K, and CH4Si at 800-950 K. No molecular adspecies is found above 1100 K, indicating complete conversion of DSB to silicon carbide. Through this study, we demonstrate that RIS gives more reliable evidence than SIMS for identification of surface molecules. (C) 2000 Elsevier Science B.V. All rights reserved.