Highly sensitive detection of adsorbed species on a SiO2 surface by reflection-absorption infrared spectroscopy

A SiO2(50 nm)/buried W(70 nm)/Si(100) sample was prepared and used to detect vibrational modes of submonolayer adsorbates on a SiO2 surface by reflection-absorption infrared spectroscopy (RAIRS). Enhancement of the RAIRS signal by the W layer was clearly shown by comparing v(OD) signal of surface deuteroxyl species to that on a SiO2(50 nm)/Si(100) sample. Utilizing the SiO2/W/Si sample, RAIRS was used to follow the reversible reaction of surface hydroxyl species of SiO2 with methanol to give surface methoxy species.