Improved performance of gate-last FDSOI tunnel field-effect-transistors (TFETs) with modulating Al2O3 composition in atomic layer deposited HfAlOx gate dielectrics

Abstract

We have studied the electrical characteristics of both n-type and p-type fully depleted silicon on insulator (FD-SOI) tunnel field-effect transistors (TFETs) by modulating Al2O3 fraction (25%, 50%) within atomic layer deposited HfAlOx gate dielectric. Compared to HfO2 alone, lower subthreshold swing (S.S), higher Ion/Ioff, and stronger threshold voltage (Vth) immunity against electrical stress are obtained for both n-type and p-type TFETs by adopting nano-laminated atomic layer deposited HfAlOx, attributed to the increased band gap and interfacial layer scavenging effect.