Growth and electrical characterization of laser ablated highly oriented zirconium titanate thin films in a metal–oxide semiconductor configuration

Abstract

Highly oriented zirconium titanate (ZrTiO4) thin films were deposited along the (020) direction on a p-type Si substrate using the pulsed excimer laser ablation technique. X-ray diffraction and energy dispersive analysis of ZrTiO4 thin films reveal that they exhibit excellent phase and stoichiometry, respectively. Secondary ion mass spectrometer analysis has revealed that the presence of less thick native oxide is unavoidable and that a nearly sharper interface exists at the semiconductor–insulator interface. Electrical characterization was carried out on the highly oriented ZrTiO4 thin films. The density of interface states and fixed oxide charges were calculated using capacitance–voltage (C–V) analysis and the obtained dielectric constant was greater than 19. The annealed films exhibited higher dielectric constant and lower fixed oxide charges than the as-grown thin films. The influence of temperature on the response of the C–V characteristics has been studied and the recombination–generation of charge carriers was found to be responsible for the transition of the C–V curve from high frequency to low frequency. The conduction mechanism was examined using dc leakage current characteristics, revealing the bulk limited Poole–Frenkel conduction mechanism as the dominant mechanism in the ZrTiO4 thin films in a metal–oxide semiconductor capacitor.