Characteristics of cylindrical surrounding-gate GaAs_xSb_(1-x)/In_yGa_(1-y)As heterojunction tunneling field-effect transistors

A Ⅲ-Ⅴ heterojunction tunneling field-effect transistor(TFET) can enhance the on-state current effectively,and GaAsSb/InGaAs heterojunction exhibits better performance with the adjustable band alignment by modulating the alloy composition.In this paper,the performance of the cylindrical surrounding-gate GaAsSb/InGaAs heterojunction TFET with gate-drain underlap is investigated by numerical simulation.We validate that reducing drain doping concentration and increasing gate-drain underlap could be effective ways to reduce the off-state current and subthreshold swing(SS),while increasing source doping concentration and adjusting the composition of GaAsSbInGaAs can improve the on-state current.In addition,the resonant TFET based on GaAsSb/InGaAs is also studied,and the result shows that the minimum and average of SS reach 11 mV/decade and 20 mV/decade for five decades of drain current,respectively,and is much superior to the conventional TFET.

A Ⅲ-Ⅴ heterojunction tunneling field-effect transistor(TFET) can enhance the on-state current effectively,and GaAs_xSb_1_x/In_yGa_1_yAs heterojunction exhibits better performance with the adjustable band alignment by modulating the alloy composition.In this paper,the performance of the cylindrical surrounding-gate GaAs_xSb_1_x/In_yGa_1_yAs heterojunction TFET with gate-drain underlap is investigated by numerical simulation.We validate that reducing drain doping concentration and increasing gate-drain underlap could be effective ways to reduce the off-state current and subthreshold swing(SS),while increasing source doping concentration and adjusting the composition of GaAs_xSb_1_xIn_yGa_1_yAs can improve the on-state current.In addition,the resonant TFET based on GaAs_xSb_1_x/In_yGa_1_yAs is also studied,and the result shows that the minimum and average of SS reach 11 mV/decade and 20 mV/decade for five decades of drain current,respectively,and is much superior to the conventional TFET.