Annealing Dependence of Solution-Processed Ultra-Thin ZrOx Films for Gate Dielectric Applications

Ultra-thin ZrOx thin films on Si substrates were prepared by sol-gel technique and processed with different methods (baked on hot plate at 150 °C, annealed at 500 °C in furnace, and photo-annealed under UV light). The decomposition of the organic groups and the formation of Zr-O bonding in the ZrOx thin films were confirmed by Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. It is found that the ZrOx thin film annealed under UV light shows decent characteristics, including an ultra-small surface roughness, a low leakage current density of 10(-9) A/cm2 at 1 MV/cm, a large breakdown electric field of 9.5 MV/cm, and a large areal capacitance of 775 nF/cm2.