Multi-level storage in cleaved-gate ferroelectric FETs investigated by 3D phase-field-based quantum transport simulation

In this work, we investigate the feasibility of cleaved-gate ferroelectric FET (CG-FeFET) as multi-level cell (MLC) memory devices, by conducting 3-dimensional quantum transport simulations based on time-dependent-Ginzburg–Landau equation, and the non-equilibrium Green’s function method. Our results indicate that CG-FeFET can achieve multi-level operations by utilizing different thicknesses of the ferroelectric layer. We analyze the influence of electron–phonon interaction and also verify that CG-FeFET is robust to noise. Furthermore, we identify the critical role of the spacing between two ferroelectric layers in determining the memory window, considering the effects of polarization cancellation and electrostatic coupling. These findings provide valuable insights into designing stable and reliable nonvolatile memory technologies, which could offer potential solutions for high-density memory requirements.