Design and Simulation of Steep-Slope Silicon Cold Source FETs With Effective Carrier Distribution Model
Weizhuo Gan, Raphaël J. Prentki, Fei Liu, Jianhui Bu, Kun Luo, Qingzhu Zhang, Huilong Zhu, Wenwu Wang, Tianchun Ye, Huaxiang Yin, Zhenhua Wu, Hong Guo
Abstract
The cold source field-effect transistor (CSFET), enabled by novel source engineering, is a promising alternative to achieve sub-60 mV/dec steep-slope switching. For the first time, we develop an industry-standard TCAD approach for the CSFET with an effective cold carrier density of states (DOS) model which captures the underlying physics of DOS engineering, cold carrier injection, and thermalization in the device. The simulation scheme uses nonequilibrium Green's function (NEGF) simulation for calibration. The effects of source engineering, rethermalization, and channel tunneling are extensively investigated on a Si-based double-gate CSFET. Its merits are highlighted by comparison with a conventional MOSFET under various temperatures, thicknesses, and gate lengths, showing improved I <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">ON</sub> I <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">OFF</sub> in ultrascaled MOSFET.