Dynamically Tunable Subthermionic Subthreshold Swing and Hysteresis in a Hf0.5Zr0.5O2-Based Ferroelectric Device Unit

In this article, we propose a universal way to tune subthermionic subthreshold swing (SS) and hysteresis dynamically in an amphibious basic functional unit, which can operate in memory- or steep-slope logic mode. The observed largest hysteresis is 4.59 V with gate-voltage tunability down to approximately 0 V. A sub-60 mV/decade SS can also be dynamically achieved and the smallest value is as low as 19.9 mV/decade. Theoretical simulations based on the multidomain temporal Landau–Khalatnikov equation clearly show that this dynamic tunability is endowed by the external bias-dependent competition between the ferroelectric polarization of Hf0.5Zr0.5O2 (HZO) and the charge screening effect of the control transistor. This work proposes the way to dynamically modulate SS to sub-60 mV/decade independent of the gate-stack, which breaks the limitations of conventional static optimization and shows potential in promoting the development of HZO-based steep-slope and multifunctional devices.