High Performance and Self-rectifying Hafnia-based Ferroelectric Tunnel Junction for Neuromorphic Computing and TCAM Applications

Abstract

We experimentally demonstrated high performance and self-rectifying hafnia based ferroelectric tunnel junction (FTJ) using stress engineering, diffusion barrier technology, and imprint field effect for neuromorphic computing and logic in memory application. In TiN/HZO/TaN/W stacked FTJ, W bottom electrode which has low thermal expansion coefficient enables to stabilize the ferroelectric o-phase even at ultra-thin HZO film, and TaN layer suppresses the diffusion of W atoms into ferroelectric HZO layer, resulting in reduction of leakage current and giant TER value of 100. In addition, highly asymmetric switching characteristics with rectifying ratio of 1000 is achieved using imprint field effect induced by positive fixed charges nearby bottom interface. The proposed device provides a viable solution for high performance, low power and high-density synaptic devices and TCAM applications.