Ferroelectric Tunnel Junction for Dense Cross-Point Arrays

Cross-point array (CPA) structure memories using a memristor are attracting a great deal of attention due to their high density integration with a 4F² cell. However, a common significant drawback of the CPA configuration is crosstalk between cells. To date, the CPA structure using a redox-based memristor has restrictions to minimize the operating current level due to their resistive switching mechanism. This study demonstrates suitable characteristics of a ferroelectric tunnel junction (FTJ) for the memristor of the CPA structure using an electrostatic model. From the FTJ of the Au/p-type Pr_0.98Ca_0.02MnO₃ (4 nm)/ BaTiO₃ (4.3 nm)/n-type Ca_0.98Pr_0.02MnO₃ (3 nm)/ Pt(111) structure, which has a higher and thicker potential barrier, a good memristive effect for the CPA structure with a high nonlinear current-voltage curve and low current operation, was obtained by Δ Fowler-Nordheim tunneling with effectively blocked direct tunneling and thermionic emission. The FTJ demonstrated reduced sneak current and the possible for high nonlinearity.