Study of TiO2Thin Films for Ion Sensitive Field Effect Transistor Application with RF Sputtering Deposition

Thin films of titanium dioxide (TiO 2 ) have been deposited on (100) silicon wafers by RF sputtering from a 99.99% pure TiO 2 target, which yield film with yielded films with attractive physical and mechanical properties. Furthermore, the dielectric constant of the TiO 2 thin films covers a wide range, and the films can be tested for use as protective and isolating layers. In this work, we study the sensitivity of the TiO 2 films applied to the ion sensitive field effect transistor (pH-ISFET). In order to examine the properties of the surface adsorption, pH response and corrosion of the sensing material, the EIS structure is often employed. The C – V measurement is well known for the characterization of a MOS capacitance, which is also suitable for characterizing an EIS structure. After TiO 2 thin films were annealed at 500°C in oxygen for 1 h, the sensitivities of TiO 2 gate pH-ISFET and EIS devices were determined by the I DS – V G and C – V curves that shifted in the various pH buffer solutions. Furthermore, X-ray photoelectron spectroscopy (XPS) was used to analyze the chemical state and composition of the titanium dioxide films. The results show that Ti 4+ and O 1s states exist on the sputtered surface and atomic concentrations of both were measured.