Current Transport Analysis of ZrO2 Thin Films: Effects of Post-deposition Annealing

Abstract

We report on the effects of post-deposition annealing on the electrical properties and the dielectric performance of atomic layer-deposited ZrO2 thin films investigated by using capacitance-voltage and current-voltage measurements. ZrO2 films crystallized by post-deposition annealing in vacuum showed an enhanced dielectric constant and energy band gap, but the leakage current was increased. The Poole-Frankel and the trap assisted tunneling mechanisms were considered to be the major leakage current conduction processes and the charge trap energy level was reduced from 1.09 - 1.13 eV to 0.81 - 0.84 eV by post-deposition annealing. The increase in the leakage current in the crystallized films can be explained by considering structural defect relaxation or grain boundary formation.