Work-Function Variation Effects of Tunneling Field-Effect Transistors (TFETs)

Abstract

The work-function variation (WFV) effects of tunneling field-effect transistors (TFETs) are discussed for the first time. According to the 3-D device simulation results, TFETs are less immune to the WFV than metal-oxide-semiconductor FETs (MOSFETs) in terms of subthreshold swing (S) and threshold voltage (V-th). TFETs show similar to 1.4x larger V-th standard deviation (sigma V-th) and similar to 4.6x larger S standard deviation (sigma S) than MOSFETs at high drain voltage (V-D). It is because TFET characteristics are mainly determined by WF values of metal grains near to the source region where band-to-band tunneling occurs.