Structural heterogeneity in chalcogenide glass films prepared by thermal evaporation

GeSe2 and Ge28Sb12Se60 chalcogenide glass thin films have been deposited on single crystal silicon substrates by vacuum thermal evaporation. The surface morphology of these films has been investigated by field emission-scanning electron microscopy and atomic force microscopy, revealing heterogeneities in their microstructure consisting of granular regions ∼15–50 nm in size, which were coarser in the case of the GeSe2 films. Typical RMS film surface roughness values were ∼0.9–1.3 nm.