Selective wet-etching and characterization of chalcogenide thin films in inorganic alkaline solutions

This paper deals with sensitivity of chalcogenide based photoresists in inorganic alkaline solutions. The thin films of As33S67, As33S50Se17, As33S33.5Se33.5, As33S17Se50, and As33Se67 were studied. The selective wet-etching was carried out using NaOH, Na2S and (NH4)2S alkaline solutions. The different sensitivity according to sample composition and used etching solution were found. Chalcogenide films as a potential photoresists could be classified either as ‘high-contrast’ or ‘low-contrast’ depending on the sample compositions, type of etchant and its concentration or on incident light energy.