Comparative study of evaporated germanium and silicon films by inelastic electron tunneling spectroscopy

Vibrational spectra of thin (0.2-1.0 nm) films of evaporated germanium on alumina surfaces have been measured by inelastic electron tunneling spectroscopy. The tunneling spectra of the evaporated Ge films were compared with those of the Si films. The tunneling spectra were also compared with the vibrational spectra of surface species on crystalline Ge formed from reactions with atomic hydrogen, water, and oxygen measured by high-resolution electron energy loss spectroscopy and multiple internal reflection infrared spectroscopy, and they showed the formation of germanium hydride species. Monohydride is predominantly formed in films prepared both in high vacuum (10 -6 Torr) and in an atmosphere of H 2 O (10 -5 Torr)