Dielectric characteristics and chemical structures of Nb₂O₅ thin films grown by sol-gel techniques

Abstract

Nb₂O₅ thin films were produced on silicon substrates by sol-gel spin-coating technique. The films were heat-treated at temperatures ranging from 600°C to 1000°C in oxygen atmosphere, and their crystalline phases, chemical states, and dielectric characteristics were investigated by X-ray diffractometry (XRD), Auger electron spectroscopy(AES), and C-V measurements, respectively. The Nb₂O₅ thin films annealed at temperatures ranging from 600°C to 1000°C as well as the powders annealed in the temperature region from 600°C to 800°C are of the T-type structure, while the powders annealed at 1000°C are of the H-type structure. The films heat-treated at temperatures ranging from 600°C to 800°C exhibit dielectric constants of less than 20, while the films annealed at 1000°C show a dielectric constant of 28.