Comparison of 2-D MoS<sub>2</sub> and Si Ferroelectric FET Nonvolatile Memories Considering the Trapped-Charge-Induced Variability
You-Sheng Liu, Pin Su
Abstract
This brief investigates scaled 2-D MoS <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> ferroelectric field-effect transistor (FeFET) nonvolatile memories (NVMs) considering the trapped-charge-induced variability with the aid of Technology Computer Aided Design (TCAD) atomistic simulations. Our study indicates that, compared with the Si channel, the monolayer MoS <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> channel with larger electron affinity and bandgap energy can result in an FeFET NVM with larger memory window (MW). Moreover, due to its lower channel permittivity and channel thickness, the 2-D MoS <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> FeFET possesses a superior immunity to trapped-charge-induced variability, and the gap in MW between MoS <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> and Si FeFETs enlarges under the presence of trapped charges. Besides, due to its atomically thin channel thickness and superior electrostatic integrity, the scaled 2-D MoS <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> FeFET possesses a remarkably better read margin than the Si counterpart. Our study may provide insights for future scaling of FeFET NVMs.