Design and Optimization of Germanium-Based Gate-Metal-Core Vertical Nanowire Tunnel FET

In this paper, a germanium-based gate-metal-core vertical nanowire tunnel field effect transistor (VNWTFET) has been designed and optimized using the technology computer-aided design (TCAD) simulation. In the proposed structure, by locating the gate-metal as a core of the nanowire, a more extensive band-to-band tunneling (BTBT) area can be achieved compared with the conventional core–shell VNWTFETs. The channel thickness (T(ch)), the gate-metal height (H(g)), and the channel height (H(ch)) were considered as the design parameters for the optimization of device performances. The designed gate-metal-core VNWTFET exhibits outstanding performance, with an on-state current (I(on)) of 80.9 μA/μm, off-state current (I(off)) of 1.09 × 10(−12) A/μm, threshold voltage (V(t)) of 0.21 V, and subthreshold swing (SS) of 42.8 mV/dec. Therefore, the proposed device was demonstrated to be a promising logic device for low-power applications.