QUENCHING OF METAL STICKING BY PHOTOOXIDATION OF AN AMORPHOUS-SEMICONDUCTOR - ZN ON GES2

The sticking probability of Zn on amorphous GeS2 is greatly reduced wh en the UHV-prepared semiconductor film is photo-oxidized in the presen ce of band-gap radiation. The phenomena underlying this interesting ef fect have been elucidated in a kinetic and structural study using elec tron spectroscopy and x-ray-absorption spectroscopy. Selective photo-o xidation of Ge sites strongly suppresses the formation of Ge-Zn bonds at the interface: these act as nucleation sites for the growing metal film. A consistent picture emerges that also accounts for the very dif ferent behavior encountered during deposition of Ag films with and wit hout photo-oxidation in the closely related Ag/GeS2 system.