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

D Mohata,J Fastenau,M Hudait,A W K Liu,D Lubyshev,B Rajamohanan,T Mayer,S Datta

doi:10.1109/led.2012.2213333

Abstract

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 0.4 Sb 0.6 /In 0.65 Ga 0.35 As (Eb eff = 0.31 eV) and high-stagger GaAs 0.35 Sb 0.65 /In 0.7 Ga 0.3 As (Eb eff = 0.25 eV) hetj TFETs are fabricated, and their electrical results are compared with the In 0.7 Ga 0.3 As homojunction (homj) TFET (Eb eff = 0.58 eV). Due to the 57% reduction in Eb eff , the GaAs 0.35 Sb 0.65 /In 0.7 Ga 0.3 As hetj TFET achieves 253% enhancement in I ON over the In 0.7 Ga 0.3 As 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.

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