Physical Insights Into the Nature of Gate-Induced Drain Leakage in Ultrashort Channel Nanowire FETs

Abstract

In this paper, we demonstrate that the lateral band-to-band tunneling component of gate-induced drain leakage (GIDL) leads to the formation of a parasitic bipolar junction transistor (BJT) in the OFF-state (gate voltage = 0.0 V) of nanowire FETs (NW FETs). We discuss in detail the difference in the nature of GIDL, i.e., drain current dependence on the negative gate voltage (VGS ≤ 0 V) for different NW FET configurations. Furthermore, we show that the parasitic BJT action is significant in NW junctionless accumulation mode FET (JAMFET) and NW MOSFET in the OFF-state and diminishes as the gate voltage becomes negative. Using calibrated 3-D simulations, we investigate the impact of scaling on the NW FETs and show that the enhanced band gap due to the quantum confinement effect facilitates the scaling of the NW FETs to the sub-5-nm regime. In addition, we propose the use of a lightly doped drain extension to increase the ON-state to OFF-state current ratio (ION/IOFF) of NW JAMFET and NW MOSFET.