71 mV/dec of sub-threshold slope in vertical tunnel field-effect transistors with GaAsSb/InGaAs heterostructure

We fabricated a vertical tunnel field-effect transistor (TFET) with a GaAsSb/InGaAs heterojunction using a 5-nm-thick Al₂O₃ dielectric. The 26-nm width of the narrow channel mesa structure was confirmed using citric acid solution. The minimum sub-threshold slope (SS) was 71 mV/dec. On the basis of our simulated and experimental results, the SS was estimated to be 54 mV/dec for an effective oxide thickness (EOT) of 1 nm.