Structural, Electrical and Dielectric Properties of DC Reactive Magnetron Sputtered ZrO2 Films for Metal-Oxide-Semiconductor Devices
Thin films of zirconium oxide (ZrO2) were deposited by DC magnetron sputtering of metallic target of zirconium on to quartz and p-Si (100) substrates at various oxygen partial pressures in the range 2x10-2 - 6x10-2 Pa. The crystallinity, surface morphology and optical absorption of the films were influenced by the oxygen partial pressure. X-ray photoelectron spectroscopic studies revealed that the films formed at oxygen partial pressure of 4x10-2 Pa were of stoichiometric ZrO2. X-ray diffraction profiles indicated that the grown films were of nanocrystalline with crystallite size increased from 5 nm to 9 nm with increase of oxygen partial pressure from 2x10-2 Pa to 6x10-2 Pa. The optical band gap of the films increased from 5.65 to 5.80 eV and the refractive index increased from 2.02 to 2.08 with the increase of oxygen partial pressure from 2x10-2 to 6x10-2 Pa respectively. The fabricated MOS structure with the configuration of Al/ZrO2/p-Si showed the dielectric constant of 22 and leakage current density of 1x10-6 A/cm2.