Ferroelectric/Semiconductor/Tunnel-Junction Stacks for Nondestructive and Low-Power Read-Out Memory

Abstract

We demonstrate that a tunnel junction connected in series to the ferroelectric (FE) via a semiconductor (SC) layer can be used to 1 probe the polarization state in an FE thin-film capacitor. A thermodynamic analysis is carried out to demonstrate the carrier depletion and accumulation at the SC/tunnel-junction interface as a function of the polarization direction in the FE layer. Our results indicate that the tunnel junction’s polarization and electroresistance depend on those of the main FE bit for a carefully chosen doping of the SC. This would allow measurement of the tunnel current to probe the polarization state of the FE bit nondestructively with much lower power consumption than the destructive technique where the displacement current at the switching of polarization is read. The proposed approach considers an FE/SC/tunnel-junction stack with top and bottom electrodes and is analogous to the Giant Magnetoresistance (GMR) stacks where the resistance change is indicative of magnetization orientation of the pinned and soft layers, implying the binary bit in the storage medium.