Symmetrical TiO2 nanowire (NW) arrays have been synthesized on Si by using glancing angle deposition technique. The Raman spectrum of TiO2 thin film (TF) and TiO2 NWs sample indicates the presence of both anatase and rutile phase TiO2. The electrical properties of the vertically ordered TiO2 NW arrays have been measured. The leakage current for high-k TiO2/Si capacitance reduced with the addition of TiO2 NWs on 30 nm TF. TiO2 NW dielectric was employed to achieve large conduction band offset between oxide layer and Si. A high gate capacitance has been observed due to NW effect. The barrier height between Ag/TiO2-NW interfaces was 0.9 eV and an exclusively lowest leakage current of 8.8 × 10−7 A/cm2 (at +1 V) was reported for the TiO2 NW device.