Barrier-Engineered Arsenide–Antimonide Heterojunction Tunnel FETs With Enhanced Drive Current

In this letter, we experimentally demonstrate enhancement in drive current I_ON and reduction in drain-induced barrier thinning (DIBT) in arsenide-antimonide staggered-gap heterojunction (hetj) tunnel field-effect transistors (TFETs) by engineering the effective tunneling barrier height Eb_eff from 0.58 to 0.25 eV. Moderate-stagger GaAs_0.4Sb_0.6/In_0.65 Ga_0.35As (Eb_eff = 0.31 eV) and high-stagger GaAs_0.35Sb_0.65/In_0.7Ga_0.3As (Eb_eff = 0.25 eV) hetj TFETs are fabricated, and their electrical results are compared with the In_0.7Ga_0.3As homojunction (homj) TFET (Eb_eff = 0.58 eV). Due to the 57% reduction in Eb_eff, the GaAs_0.35Sb_0.65/In_0.7Ga_0.3As hetj TFET achieves 253% enhancement in I_ON over the In_0.7Ga_0.3As homj TFET at V_DS = 0.5 V and V_GS - V_OFF = 1.5 V. With electrical oxide thickness (Toxe) scaling from 2.3 to 2 nm, the enhancement further increases to 350 %, resulting in a record high I_ON of 135 μA/μm and 65% reduction in DIBT at V_DS = 0.5 V.