Negative resist behavior of obliquely deposited Ge-Sb-Se thin films

Abstract

The photon and electron-beam induced changes in the selective solubility of Ge-Se-Sb films have been investigated to show that these films can be used as a negative resist. The formation of Sb₂Se₃ on the top of the film surface after exposure, as confirmed by x-ray diffraction and x-ray photoelectron spectroscopy studies, gives rise to a negative tone behavior. The addition of 10 at. % of Sb in the GeSe₃ films saturates the change in the chemical solubility after photo- and electron-beam exposures. The chemical solubility difference can be increased by increasing the angle of deposition and is maximum at 80°. Contrast (γ) and sensitivity (s) values of 2.85 and ˜10²⁰ photons/cm², respectively, for photons, and 4.2 and 6× 10^-5 C/cm² for electrons have been obtained.