Switching Performance of Nanotube Core-Shell Heterojunction Electrically Doped Junctionless Tunnel Field Effect Transistor

Abstract: In this paper, a novel tunnel field effect transistor (TFET) is introduced, thatdue to its superior gate controllability, can be considered as a promising candidate forthe conventional TFET. The proposed electrically doped heterojunction TFET(EDHJTFET) has a ۳D core-shell nanotube structure with external and internal gatessurrounding the channel that employs electrostatically doping rather than ionimplantationfor creating the tunneling junction. The staggered type InAs/GaAs۰.۱Sb۰.۹heterojunction devices, considerably amplifies the band to band tunneling rate. Theeffect of device geometry and physical design parameters on the performance of thedevice are comprehensively investigated and cut off frequency of ۲۰۰GHz, on/offcurrent ratio of ۹.۴۱×۱۰۸ and subthreshold swing of ۸.۷ mV/dec are achieved. Thesensitivity analysis reveals that core/shell control gate workfunction and doping densityare critical design parameters that may affect the device performance. Moreover, theinsensitivity of off-state current to the drain voltage variation and channel length scalingsignifies the application of this device in nanoscale regime.

Keywords:

Junctionless transistor , Tunnel field effect transistor , Band to band tunneling , Subthreshold swing , Gate workfunction