Annealing effects on the structure and electrical characteristics of amorphous Er 2 O 3 films

Amorphous Er2O3 films are deposited on Si (001) substrates by using reactive evaporation. This paper reports the evolution of the structure, morphology and electrical characteristics with annealing temperatures in an oxygen ambience. X-ray diffraction and high resolution transimission electron microscopy measurement show that the films remain amorphous even after annealing at 700 °C. The capacitance in the accumulation region of Er2O3 films annealed at 450 °C is higher than that of as-deposited films and films annealed at other temperatures. An Er2O3/ErOx/SiOx/Si structure model is proposed to explain the results. The annealed films also exhibit a low leakage current density (around 1.38 × 10−4 A/cm2 at a bias of −1 V) due to the evolution of morphology and composition of the films after they are annealed.