Total Ionizing Dose Effects and Proton-Induced Displacement Damage on MoS2-Interlayer-MoS2 Tunneling Junctions

Tunneling-dominated charge transport is demonstrated in vertically stacked MoS
₂
/interlayer/MoS
₂
heterostructures with Al
₂
O
₃
, hexagonal boron nitride (h-BN), and HfO
₂
dielectrics. All devices are highly resistant to 10-keV X-ray irradiation. Only small transient changes in X-ray-induced photocurrent are observed as a result of trap creation in the thin interlayer dielectric, with rapid passivation. Samples with Al
₂
O
₃
and h-BN interlayer dielectrics show significant increases in conduction current during proton irradiation, due to displacement-damage-induced defects that lower the effective tunnel-barrier height. Density-functional-theory calculations provide insights into the pertinent defects. Devices with HfO
₂
interlayer dielectrics show great promise for use in radiation tolerant, ultimately scaled tunnel FETs.