Adsorption and decomposition of 1,3-disilabutane on Si (111)-7 7

Abstract The adsorption and decomposition of 1,3-disilabutane (DSB) was studied on Si (111)-7×7 in the temperature range 100–1200 K by Cs + reactive ion scattering and X-ray photoelectron spectroscopy (XPS). By combining the results of these two techniques, adspecies in the intermediate states during the decomposition of DSB were qualitatively identified and an adsorption model was proposed. At 100–150 K, DSB was found to adsorb on the surface as the C 2 H 8 Si 2 species as well as CH 4 Si and to condense molecularly on a monolayer of C 2 H 8 Si 2 adspecies. XPS indicates that the molecular species desorbs mostly at 200 K and completely at 300 K. Up to 600 K, the C 2 H 8 Si 2 adspecies are converted to CH 4 Si with increasing temperature and then above this temperature the CH 4 Si species decomposes to form the SiC film. The intensity variations of Si (2 p ) and total C (1 s ) peaks and the analysis by curve fitting of the C (1 s ) peaks suggest that one CH 4 Si species leaves the system by cleavage of C–Si bonds in C 2 H 8 Si 2 adspecies rather than to form two CH 4 Si adspecies, and the breakage probably occurs within the extremity ones in accordance with the double-bonded chemisorption character.