Estimation of steady-state leakage current in polycrystalline PZT thin films

Estimation of the steady state (or "true") leakage current J(s) in polycrystalline ferroelectric PZT films with the use of the voltage-step technique is discussed. Curie-von Schweidler (CvS) and sum of exponents (Sigma exp) models are studied for current-time J (t) data fitting. Sigma exp model (sum of three or two exponents) gives better fitting characteristics and provides good accuracy of J(s) estimation at reduced measurement time thus making possible to avoid film degradation, whereas CvS model is very sensitive to both start and finish time points and give in many cases incorrect results. The results give rise to suggest an existence of low-frequency relaxation processes in PZT films with characteristic duration of tens and hundreds of seconds. (C) 2016 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).