Performance limitations of nanowire resonant-tunneling transistors with steep switching analyzed by Wigner transport simulation

摘要

We conducted a quantum transport simulation of nanowire resonant-tunneling field-effect transistors (NW-RTFETs) based on the Wigner function model. The current-voltage characteristics of the NW-RTFETs were compared with those of the nanowire transistors and nanowire resonant-tunneling diodes. For the selection of a gate with appropriate performance, symmetric and asymmetric gates with various lengths were tested, and a symmetric gate, covering the quantum well and barrier regions, was chosen as a main gate. The source-side asymmetric gates did not produce a negative differential resistance at low gate voltages in contrast to the symmetric or drain-side asymmetric gates. Although steep switching is achieved in the negative differential resistance region, the ON/OFF current ratio (I-ON/I-OFF) is extremely low, compared to those of conventional transistors. In an attempt to increase the I-ON/I-OFF ratio, the sizes of the semiconductor cylinder and the oxide tube were changed. This study discusses the requirements for increasing the applicability of steep switching. Published under license by AIP Publishing.