Tunable Band-to-Band Tunneling and Conducting Path Transition in Local-Control-Gate Heterostructure Transistor

Transition metal dichalcogenide (TMD) material-based heterostructures have exhibited great potential for building advanced architectures in novel logic devices. A local-control-gate (LCG) transistor based on MoTe₂/MoS₂ heterostructure is fabricated and analyzed, illustrating its tunable electrical characteristics and achieving band-to-band tunneling (BTBT) enhancement with an improved peak-to-valley current ratio (PVCR) value of 3.04. Compared to the basic dual-gate tunnel field-effect transistor (TFET) structure, adding LCG at the bottom not only isolates defect-induced doping effects from the deposition of top gate dielectrics, but also paves the way for broader applications in multivalued logic and artificial intelligence. Aiming to further verify the operating mechanism of conducting path transition and electrical characteristic trends, commercial technology computer-aided design (TCAD) is systematically employed assisted by density functional theory (DFT). So that the transition of conducting paths in the heterostructure channel including interlayer quantum effects can be visibly demonstrated while applying various voltages to the LCG. In summary, this work highlights the feasibility of a new LCG structure with tunable electrical characteristics and presents DFT-assisted TCAD simulations for effective verifications.