Structural Characteristics of Amorphous Er_2O_3 Films Grown on Si(001)by Reactive Evaporation

High k dielectric Er_2O_3 were deposited on p-type Si(100)substrates by reactive evaporation using metallic Er source at room temperature in an oxygen atmosphere.The composition of the films is determined to be stoichiometric.X-ray diffraction,reflection high energy electron diffraction and high resolution transmission electron microscopy tests reveal that the films are amorphous even after thermal annealing at 700℃.The films have very flat surface after high temperature annealing.The dielectric constant of Er_2O_3 films is 12.6,an effective oxide thickness of 1.4nm is achieved,with a low leakage current density of 8×10~(-4)A/cm~2 at electric field of 1MV/cm after annealing.The obtained results indicate that the amorphous Er_2O_3 film is a promising candidate for high k gate dielectric in Si microelectronic devices.