Rapid thermal processed thin films of niobium pentoxide (Nb₂O₅) deposited by reactive magnetron sputtering

Abstract

Niobium pentoxide thin films have been deposited on silicon and platinum-coated silicon substrates by reactive magnetron sputtering. The as-deposited films were amorphous and showed good electrical properties in terms of a dielectric permittivity of about 30, and leakage current density of 10^-6 A cm^-2 at a field of 120 kV cm^-1. A rapid thermal annealing process at 800 ° C further increased the dielectric constant to 90 and increased the leakage current density to 5 × 10^-6 A cm^-2. The current-voltage characteristics observed at low and high fields suggested a combination of phenomena at different regimes of applied electric field. The capacitance-voltage characteristics performed in the metal-insulator-semiconductor configuration indicated good electronic interfaces with a nominal trap density of 4.5 × 10¹² cm^-2 eV^-1, which is consistent with the behavior observed with conventional dielectrics such as SiO₂ on silicon surfaces.