Study of novel fully-depleted Ge-on-Insulator n-channel MOSFET with field plate structure for improvement in GIDL and on/off characteristics

In this paper, a novel structure of the fully-depleted Ge-on-Insulator (GOI) n-channel MOSFET with field plate is proposed and studied by two-dimensional numerical simulation. The results indicate that the gated-induced drain leakage (GIDL) of the fully-depleted GOI NMOSFET with field plate (FD-FP NMOSFET) is suppressed effectively. Besides, off-state current Ioff decreases by 2 orders of magnitude compared with the device without field plate. The impacts of the distance of field plate from the drain Lcb and the difference of work function between field plate metal and channel material Φfps on the electrical characteristics of FD-FP NMOSFET are investigated. FD-FP NMOSFET with a Φfps of 0 eV and a Lcb of 5 nm, demonstrates a reduction in Ioff by more than 3 orders of magnitude as compared with the control device. An on/off ratio Ion/Ioff = 2.57 × 107, and a sub-threshold swing of 76.8mV/decade are achieved.