Impact of the ferroelectric layer thickness on the resistive switching characteristics of ferroelectric/dielectric structures

In the present work, the effect of the ferroelectric layer thickness on the resistive switching (RS) characteristics of 0.5 Ba(Zr0.2Ti0.8)O3-0.5 (Ba0.7Ca0.3)TiO3 (BCZT)/HfO2:Al2O3 (HAO) structures deposited on Pt-Si substrates in a metal-dielectric-ferroelectric-metal configuration is investigated. The polarization-electric field hysteresis loops disclose the ferroelectric nature of the Pt/BCZT/ HAO/Au structures and reveal that the remnant polarization and the coercive field decrease with the increase in the BCZT ferroelectric layer thickness. Furthermore, the RS behavior is observed in Pt/BCZT/HAO/Au structures and is attributed to the barrier variation at the BCZT/HAO interface caused by the ferroelectric polarization flipping. Besides, it is also shown that the RS ratio and the switching field can be tuned by the thickness of the ferroelectric layer. This work intends to be a first step to build an alternative stack that provides an efficient way to develop dielectric-ferroelectric structures for RS memory devices with low power consumption.This work was supported by (i) Portuguese Foundation for Science and Technology (FCT) in the framework of the Strategic Funding Contract No. UID/FIS/04650/2013 and (ii) Project Norte-070124-FEDER-000070 Nanomateriais Multifuncionais. The author J.P.B.S. is grateful for financial support through the FCT Grant No. SFRH/BPD/92896/2013. The author K.C.S. thanks UGC and DST-SERB, Government of India, for the funds through Grant Nos. F.45(59-FRP/2014(BSR)) and ECR/2017/000068, respectively. The authors would like to thank also Engineer Jos e Santos for the technical support at the Thin Films Laboratory (University of Minho).