Glass Etching Initiated by Excimer Laser Photolysis of CF2Br2

Article abstract of DOI:10.1021/j100400a011

KrF and ArF excimer laser irradiation of glass surfaces immersed in gaseous CF2Br2 is found to induce etching.The etch mechanism is considered to be nonthermal on the basis of the small value of the glass absorption coefficient and wavelength variable etching experiments.The etch rate dependence on surface fluence is presented for three pressures.SEM photos reveal a rough surface morphology in the etched region that apparently is not a chemical effect but results solely from the laser irradiation.Photochemical and spectroscopic analysis of the irradiated gas provides evidence for CF2 and CF2Br as being major photolysis products.C2F4 was also found to cause etching at 248 and 193 nm.This is evidence that CF2, resulting from C2F4 photolysis, is alone capable of initiating glass etching in the presence of laser light.The paper concludes by discussing the observed inability of the CF3 releasing parent gases CF3Br and CF3I to significantly etch glass when irradiated in their appropriate absorption bands.