Hall mobility measurements and chemical stability of ultrathin, methylated Si(111)-on-insulator films

The chemical and electronic properties of 10-20 nm thick, methylated Si(111)-on-insulator (CH3/Si(111)(SOI)) thin films, prepared using a wet chemical chlorination/methylation procedure, are investigated. X-ray photoelectron spectroscopy reveals that CH3/Si(111)sol is resistant to oxidation upon exposure to air and to various device fabrication schemes and associated chemicals. Temperature-dependent Hall mobility measurements yield results that are dependent upon the duration of the chlorination step. For short-time chlorination steps, bulklike mobilities are observed, and the dominant scattering mechanism arises from ionized impurities. For longer time chlorination steps, surface roughness or neutral impurity scattering limit the carrier mobilities.