Photoinduced etching of thin films of chalcogenide glassy semiconductors

Photoinduced enhancement of the solubility of annealed films made of chalcogenide glassy semiconductors (ChGSs) in amine-based selective etchants has been observed. The etching rate increases with the illumination intensity, and its spectral dependence is correlated with absorption in the film at the absorption edge. It is demonstrated that the new photoinduced effect enables a photolithographic process (including interference lithography) to occur on ChGS layers, annealed at a temperature close to the glass-transition temperature of a chalcogenide glass by simultaneous illumination and selective etching of layers of this kind. A possible mechanism for the photoinduced etching of ChGSs is discussed.