Electron tunneling spectroscopy study of amorphous films of the gate dielectric candidates LaAlO₃ and LaScO₃

Electron tunneling spectroscopy (ETS) was used to study amorphous LaAl O3 and LaSc O3 thin film gate dielectrics for silicon metal-oxide-semiconductor structure. These gate dielectrics were prepared by molecular-beam deposition on (100) Si substrates. The authors have obtained vibrational modes for amorphous LaAl O3 and LaSc O3 thin films from the ETS spectra, which provide information about the chemical bonding in these films and the interface with silicon. Traps and defects in amorphous LaAl O3 thin films are revealed in the ETS spectra, and their physical locations and energy levels are identified.