Adsorption and decomposition of methylsilanes on Si 100/

We have investigated in-situ the adsorption and thermal decomposition of methylsilanes, SiH x CH3.4yx xs1–3., on Si 100. 2=1., using infrared absorption spectroscopy IRAS.in the multiple internal reflection geometry. IRAS spectra revealed that at initial stages of adsorption, monohydride –SiH.and CH3-substituted hydride species –SiH x CH3.3yx.are generated with monohydride species being dominant. We suggest that upon room temperature adsorption of methylsilanes, breaking of the Si`H bonds of methylsilane is favored over that of the Si`C bonds. It is found that the dissociative adsorption of SiH3 CH3.exhibits the second-order kinetics. Due to thermal annealing, surface species –SiHx CH3.3yx are thermally decomposed to generate surface Si`H and Si`C bonds, and subsequently H2 desorption from the Si`H bonds occurs. q2000 Elsevier Science B.V. All rights reserved