Enhancement of off-state characteristics in junctionless field effect transistor using a field plate

In this paper, a novel junctionless field effect transistor (JLFET) is proposed. In the presence of a field plate between gate and drain, the gate-induced drain leakage (GIDL) effect is suppressed due to the decrease of lateral band-to-band tunneling probability. Thus, the off-state current I_off, which is mainly provided by the GIDL current, is reduced. Sentaurus simulation shows that the I_off of the new optimized JLFET is reduced by~2 orders and its sub-threshold swing can reach 76.8 mV/decade with little influence on its on-state current I_on, so its I_on/I_off ratio is improved by 2 orders of magnitude compared with that of the normal JLFET. Optimization of device parameters such as Φ_fps (the work difference between field plate and substrate) and L_FP (the length of field plate), is also discussed in detail.