Monohydride signature as a key predictor of successful Si(110) surface functionalization

Abstract

Methyl-terminated (110)-oriented silicon surfaces have been prepared from monohydride-terminated, H–Si(110) surfaces using a chlorination/alkylation procedure. Transmission infrared spectroscopy of the H–Si(110) surfaces showed absorption features indicating monohydride structures along the [−110] direction. X-ray photoelectron spectroscopy was used to characterize the methyl-terminated, CH₃–Si(110), surfaces. Surface coverage calculations revealed 0.83 of an equivalent monolayer coverage for methyl-terminated Si(110) surfaces. No oxidation of silicon was observed in the high-resolution Si 2p spectra and the samples were stable against oxidation over time, with only 0.2 of a monolayer of surface oxide observed a month after the sample preparation. Thus, the chlorination/alkylation procedure can be used for the functionalization of monohydride Si(110) surfaces with improved long term stability.