Substrate temperature influenced ZrO2 films for MOS devices

The effect of substrate temperature on the direct current magnetron-sputtered zirconium oxide (ZrO2) dielectric films was investigated. Stoichiometric of the ZrO2 thin films was obtained at an oxygen partial pressure of 4.0 x 10(-2) Pa. X-ray diffraction studies revealed that the crystallite size in the layer was increased from 4.8 to 16.1 nm with increase of substrate temperature from 303 to 673 K. Metal-oxide-semiconductor devices were fabricated on ZrO2/Si stacks with Al gate electrode. The dielectric properties of ZrO2 layer and interface quality at ZrO2/Si were significantly influenced by the substrate temperature. The dielectric constant increased from 15 to 25, and the leakage current density decreased from 0.12 x 10(-7) to 0.64 x 10(-9) A cm(-2) with the increase of substrate temperature from 303 to 673 K.