High-current InP-based triple heterojunction tunnel transistors

We report the design and simulated performance of a GaAsSb/GaSb/InAs/InP n-type triple heterojunction (3-HJ) tunnel field-effect transistor (TFET). GaAsSb/GaSb source and InAs/InP channel HJs both increase the field imposed upon the tunnel junctions and introduce two resonant bound states. The tunneling probability, and hence the transistor on-current, are thereby greatly increased. The devices were simulated using a non-equilibrium Green function quantum transport approach and the k.p method within NEMO5. With 10−3 A/m (I OFF ) and a 0.3 V power supply V DD , we simulate 380 A/m ON-current (I ON ) at 30-nm gate length (L g ) and 275 A/m at 15-nm L g . Unlike a previously-reported high-current AlGaSb/GaSb/InAs/InGaAsSb 3-HJ design, the GaAsSb/GaSb/InAs/InP design employs channel materials to which high-quality, low-interface-state-density gate dielectrics have been demonstrated.