Laser-induced photochemical etching of SiO2 studied by x-ray photoelectron spectroscopy

Thermally grown SiO2 on Si and quartz wafers have been photochemically etched in an NF3 gas containing 0–4 mol % hydrogen by using an ArF excimer laser (193 nm in wavelength) irradiation. In situ x-ray photoelectron spectroscopy of the etched surface at each step of the photochemical reaction and in situ infrared absorption measurements of the etching gas have revealed the elementary process of etching reactions on the surface and the resulting products in the gas phase.