Abstract: The properties of a new high-k gate dielectric material LaAlO₃ were investigated. LaAlO₃ thin films
were prepared on p-type Si substrates by using radio-frequency magnetron sputtering deposition. XRD analyses show that the films are amorphous even
after annealed in O₂ at 650℃ for 15min. The capacitance equivalent oxide thickness is 2.33nm with a leakage current of 3.73mA/cm²
and 5.32×10^-4mA/cm² at V _g=+1V and --1V, respectively. The capacitance-voltage (C-V) characteristic curves show the existence of
interface states in LaAlO_₃ thin films. The hysteresis voltage in C-V curve is about 0.09V. The density of interface states calculated is about
8.35×10¹¹cm^-2. The current-voltage characteristic curves show that Pt/LaAlO₃/Si thin film is conductive only under one voltage
direction. The LaAlO₃ thin film will be a promising high-k gate dielectric for future ultra-large scale integrated devices.

Key words: gate dielectric materials, high-k, LaAlO₃ thin films