Selective etching of spin-coated and thermally evaporated As30S45Se25 thin films

•Opt. and chem. properties of evaporated and spin-coated As-S-Se thin films studied•Photo and thermo-induced structural changes investigated by Raman spectroscopy•Negative etching of evaporated and positive etching of spin-coated films observed•Diffraction grating prepared in spin-coated thin film by selective etching

Chalcogenide glasses are intensively studied materials due to their interesting optical properties such as high values of refractive index, wide transparency in IR, photosensitivity, etc. We report on the comparison of photo and thermo-induced changes in optical properties and chemical resistance of thermally evaporated and spin-coated As30S45Se25 thin films. Significantly different trends of photo-induced changes in chemical resistance in both types of thin films such as negative etching of thermally evaporated thin films and positive etching of spin-coated thin films were observed. The structural changes responsible for the observed phenomena were investigated as well.