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

Electron tunneling spectroscopy (ETS) was used to study amorphous LaAlO₃ and LaScO₃ 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 LaAlO₃ and LaScO₃ 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 LaAlO₃ thin films are revealed in the ETS spectra, and their physical locations and energy levels are identified.