A Novel Step-Channel TFET for Better Subthreshold Swing and Improved Analog/RF Characteristics
Sachin Kumar, Dharmendra Singh Yadav, Somya Saraswat, Nitish Parmar, Ritwik Sharma, Atul Kumar
Abstract
In this paper, a novel device structure is introduced to enhance ON-state current, reduce ambipolar behaviour and better subthreshold swing which is named as step channel tunnel FETs (SC-TFET). This device use small dielectric thickness at source-channel junction to improve device performance. Subthreshold Swing of device is improved due to reduced dielectric thickness at source-channel junction and ambipolar current of device is suppressed by using large dielectric thickness at drainchannel junction. For further improvement of ON-state current high-k dielectric material is introduced as oxide layer which is named as High-K SC-TFET. To analyses device performance characteristics various parameters has been calculated such as parasitic capacitance, transconductance (g <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">m</inf> ), output transconductance (g <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">ds</inf> ) and cut-off frequency (f <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">T</inf> ). Finally, a study between conventional TFET, SC-TFET and High-K SC-TFET has been investigated which shows its significant contribution in analog and RF parameters. All the simulations of purpose device have been done using TCAD device simulator.