Modification of optical and electrical properties of sol-gel-derived TiO2-doped ZrO2 gate dielectrics by annealing temperature

In this letter, annealing temperature dependence on the structure, band gap energy and electrical properties of TiO2 doped ZrO2 gate dielectrics deposited by sol-gel method at low temperature were systemically investigated. The crystalline temperature of TiO2 doped ZrO2 is up to 600 °C. The transmittance and band gap value of the ZrTiOx film were about 75% and 4.0 eV, respectively. 300 °C-annealed ZrTiOx MOS capacitor with high dielectric constant of 34.9, a small hysteresis value of 0.004 and low leakage current density of 2.7 × 10−4 A/cm2 were obtained. The dominant conduction mechanisms of Al/ZrTiO4/n-Si MOS structures were schottky emission and ohmic conduction in the low electric field and direct tunneling in the high electric field. As a result, it can be concluded that sol-gel derived ZrTiOx gate dielectric displays potential application as is a promising candidate in future MOS electronic devices.