Low-voltage short-channel MoS2 memtransistors with high gate-tunability

Neuromorphic hardware promises to revolutionize information technology
with brain-inspired parallel processing, in-memory computing, and
energy-efficient implementation of artificial intelligence and machine
learning. In particular, two-dimensional (2D) memtransistors enable
gate-tunable non-volatile memory, bio-realistic synaptic phenomena, and
atomically thin scaling. However, previously reported 2D memtransistors
have not achieved low operating voltages without compromising
gate-tunability. Here, we overcome this limitation by demonstrating
MoS2 memtransistors with short channel
lengths < 400 nm, low operating
voltages < 1 V, and high field-effect switching
ratios > 104 while concurrently achieving strong
memristive responses. This functionality is realized by fabricating
back-gated memtransistors using highly polycrystalline monolayer
MoS2 channels on high-κ Al2O3 dielectric layers. Finite-element
simulations confirm enhanced electrostatic modulation near the channel
contacts, which reduces operating voltages without compromising memristive
or field-effect switching. Overall, this work demonstrates a pathway for
reducing the size and power consumption of 2D memtransistors as is
required for ultrahigh-density integration.