Modeling of ferroelectric tunnel junctions based on the Pt/BaTiO3/Nb:SrTiO3 stack

In this paper, we report a comprehensive modeling investigation of the Pt/BaTiO3/Nb:SrTiO3 stack designed to operate as a Ferroelectric Tunnel Junction (FTJ). The analysis accounts for some specific features of the materials in the stack that are typically overlooked, such as the electric field dependence of the dielectric constant of Nb:SrTiO3 and the dependence of the dielectric constant of BaTiO3 on its thickness. Modeling results are validated through a systematic and consistent comparison with experimental data for the current–voltage characteristics of devices with different stack parameters, at different temperatures. From that, the resistive memory window of an FTJ based on the Pt/BaTiO3/Nb:SrTiO3 stack is then explored over its design space. Results allow to comprehensively assess the ultimate performance of the device, providing hints for the successful development of next-generation FTJ-based memory technologies.