This paper investigates the impact of backgate biasing (V BS ) on the drain current (I D ) of ultrathin-body III-V heterojunction tunnel FET (HTFET). Compared with homojunction TFET and III-V/Ge MOSFET, this paper indicates that HTFET exhibits significantly higher I OFF (I D at V GS = 0 V and V DS = 0.5 V) modulation efficiency and the influence of V BS rapidly decreases with increasing V GS . In addition, it is observed that the change of source available states with V BS determines the I D modulation efficiency of p-type HTFET (pHTFET). Depending on the source doping concentration and operating V GS , the I D of HTFET under forward V BS can be anomalously smaller than that at V BS = 0 V. Furthermore, the impacts of source/drain doping concentrations and junction properties are discussed and shown to be critical in determining the I D modulation efficiency of HTFET. We find that, under controlled ambipolar current, reverse backgate biasing can be utilized to suppress the I OFF of HTFET, and the modulation efficiency increases with decreasing source doping concentration. Our study may provide insights for device/circuit designs with advanced TFET technologies.
- Backgate biasing
- heterojunction tunnel FET (HTFET)
- ultrathin-body (UTB) structure