Pure and Fe doped TiO2 thin films for MOSFET Technology

Abstract

Sol-gel dip coating was used to obtain undoped and Fe doped TiO2 thin films deposited on ITO (indium tin oxide) coated glass substrate. These films were sintered at 500 ° C for 1 hour and were thoroughly characterized with respect to their crystal structure, phase transformation and elemental composition. The structural and dielectric properties of the films were characterized by XPS, TEM, and impedance analyzer. The elemental composition and the oxidation state of the elements in the films were investigated by XPS, titanium peaks were observed at 458.67eV, 457.45eV and 457.28eV that belongs to Ti +4 . The presence of Fe +3 in the samples is indicated by peaks found at 717.9eV and 709.41eV (2p1/2 and 2p3/2) state and at 743eV TEM studies confirm mostly the crystallite anatase and rutile phase for the Fe doped TiO2 films. Particle size decreased from 35 nm to 17 nm by 10-mol % iron doping. The density of interfacial states decreases with increase in iron concentration. XPS studies reveal that titanium exists in Ti +4 state in all the samples. Dielectric conductivity increased with increase in Fe concentration. Different types of polarization processes exist in different regions of frequency due to which the value of dielectric constant changes in pure as well as Fe doped TiO2 thin films. KeywordsSol-gel, anatase, rutile.