Dual Charge-Trapping Nanowire Flash Transistor for Low-Voltage High-Precision Biomimetic Synaptic Device with 1024 States

In this work, a novel longitudinal coupled flash structure using Si<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</inf>N<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</inf>/HfO<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> as dual charge trapping layers (Dual-CTFs) is proposed to expand the conventional flash devices into synapse application. The fabricated Si nanowire Dual-CTFs features superior memory and synaptic characteristics, exhibiting remarkable long-term plasticity with low pulse voltage (-2.3 V/3.7 V). Through the field-assisted charge hopping, effectively 1024 continuous conduction states are realized in a single device with good linearity and low power (~ 0.5 fJ/spike).