Modeling Multi-states in Ferroelectric Tunnel Junction

Abstract

Hafnia and Zirconia oxide (HZO) based ferroelectric tunnel junction (FTJ) has attracted a lot of attention recently due to its energy-efficient, built-in-selector, multi-level-storage, and CMOS-compatible characteristics [1] – [3] . However, FTJ is limited by its low on-state current and small on/off ratio. Furthermore, their optimal programming conditions and operating principles, such as the relation between polarization and different current states, are not fully understood yet [4] [5] . Hence, in this paper, we fabricated and measured multi-state FTJ with on/off ratio > 100. Then, we built a device model, showing the relation between HZO polarization and multi-state current. With the simulated energy band diagrams, we have identified the reasons behind the two increasing rates of current as a function of voltage. Furthermore, we qualitatively explained the asymmetric programming conditions with resistor division model and energy band diagrams.