Impact of Source Height on the Characteristic of U-shaped Channel Tunnel Field-Effect Transistor

Tunnel field-effect transistor (TFET) is very attractive in replacing a MOSFET, particularly for low-power nanoelectronic circuits. The U-shaped channel TFET (U-TFET) was proposed to improve the drain-source current with a reduced footprint. In this work, the impact of the source height (Hs) on the characteristic of the U-shaped channel tunnel field-effect transistor (U-TFET) is investigated by using TCAD simulation. It is found that with a fixed gate height (HG) the drain-source current has a negative correlation with Hs. This is because when the gate region is deeper than the source region, the electric field near the corner of the tunneling junction can be enhanced and the tunneling rate is increased. When Hs becomes very thin, the drain-source current is limited by the source region volume. The U-TFET with an n+ pocket is also studied and the same trend is observed. (C) 2017 Elsevier Ltd. All rights reserved.