Structure and electrical characterization of amorphous ErSiO films deposited by rf magnetron sputtering on Si (001)

Amorphous ErSiO films have been fabricated on p-type Si (001) substrates using rf magnetron sputtering technique. X-ray diffraction, high-resolution transmission electron microscopy, and atomic force microscopy were employed to investigate the samples. It is found that ErSiO film exhibits a flat surface, a sharp interface and superior electrical properties after post-deposition annealing in O2 ambience for 30 min at 450 C. The effective dielectric constant of the film is measured to be 14.2, and the effective oxide thickness reaches 1.9 nm, with a low leakage current density of 1.1 x 10-4 A/cm2 at an electric field of 1 MV cm-1 after annealing at 450 C. The obtained characteristics make the amorphous ErSiO films a promising substitute for SiO2 as a high-k gate dielectric. (orig.)