We have investigated in-situ the adsorption and thermal decomposition of me
thylsilanes, SiHx(CH3)(4-x) (x = 1-3), on Si(100)(2 x 1), using infrared ab
sorption spectroscopy (IRAS) in the multiple internal reflection geometry.
IRAS spectra revealed that at initial stages of adsorption, monohydride (-S
iH) and CH3-substituted hydride species (-SiHx(CH3)(3-x)) are generated wit
h 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 ads
orption of SiH3(CH3) exhibits the second-order kinetics. Due to thermal ann
ealing, surface species -SiHx(CH3)(3-x) are thermally decomposed to generat
e surface Si-H and Si-C bonds, and subsequently H-2 desorption from the Si-
H bonds occurs. (C) 2000 Elsevier Science B.V. All rights reserved.