Structure and hardness modifications induced by UV light in Ge-As-S amorphous chalcogenide films

Abstract

X-ray diffraction and transmission experiments as well as hardness measurements on virgin and ultra violet (UV)-irradiated amorphous films in the system Ge/sub x/As/sub 40-x/S/sub 60/ have been performed. The UV-light determines the film softening for x<19 and film hardening for x>19. The structure remains amorphous but the distance characteristic to medium range order (MRO) shows variations as a function of composition and irradiation time. The main effect of the UV light is the release of a significant amount of sulphur.