posted on 2024-01-25, 20:12authored byShu-Ting Yang, Tilo H. Yang, Bor-Wei Liang, Han-Chieh Lo, Wen-Hao Chang, Po-Yen Lin, Ching-Yuan Su, Yann-Wen Lan
Multiterminal
memtransistors made from two-dimensional (2D) materials
have garnered increasing attention in the pursuit of low-power heterosynaptic
neuromorphic circuits. However, existing 2D memtransistors tend to
necessitate high set voltages (>1 V) or feature defective channels,
posing concerns regarding material integrity and intrinsic properties.
Herein, we present a monocrystalline monolayer MoS2 memtransistor
designed for operation within submicron regimes. Under reverse drain
bias sweeps, our experiments reveal memristive behavior within the
device, further controllable through modulation of the gate terminal.
This controllability facilitates the consistent manifestation of multistate
memory effects. Notably, the memtransistor behavior becomes more significant
as the channel length diminishes, particularly with channel lengths
below 1.6 μm, showcasing an increase in the switching ratio
alongside a decrease in the set voltage with the decreasing channel
length. Our optimized memtransistor demonstrates the ability to exhibit
individual resistance states spanning 5 orders of magnitude, with
switching drain voltages of approximately 0.05 V. To elucidate these
findings, we investigate hot carrier effects and their interplay with
oxide traps within the HfO2 dielectric. This work highlights
the importance of memtransisor behavior in highly scaled 2D transistors,
particularly those featuring low contact resistances. This understanding
holds the potential to tailor memory characteristics essential for
the development of energy-efficient neuromorphic devices.