Interfacial and optical properties of ZrO2/Si by reactive magnetron sputtering

ZrO2 dielectric films were deposited on Si substrates by reactive magnetron sputtering technique. Interfacial and optical properties were investigated. Crystal structure was studied by X-ray diffraction. Fourier Transform Infrared Spectroscopy analysis confirmed the presence of a low-k interfacial SiO2 layer due to the excited oxygen radicals in the sputtering plasma and the physisorbed oxygen in as-deposited ZrO2 films. Optical constants were extracted based on the best spectroscopic ellipsometry fitting results. Absorption coefficients near the absorption edge were also calculated. The absorption tails in the range 4.5–4.75 eV indicated that there was a defect energy level below the conduction band of ZrO2 due to oxygen vacancies.