Drain-Engineered TFET With Fully Suppressed Ambipolarity for High-Frequency Application

• Published in: IEEE transactions on electron devices 2019-04, Vol.66 (4), p.1628-1634
• Main Authors: Uddin Shaikh, Mohd Rizwan, Loan, Sajad A
• Format: Article
• Language: English
• Subjects: Ambipolar leakage; band-to-band tunneling (BTBT); Doping; Fabrication; Field effect transistors; Junctions; Leakage; Logic gates; Semiconductor devices; Silicon; T shape; TFETs; Transconductance; tunnel field-effect transistor (TFET); Tunneling; Vertical drains
• ISSN: 0018-9383; 1557-9646
• DOI: 10.1109/TED.2019.2896674

In this paper, we propose and simulate a novel drain-engineered structure of a quadruple-gate tunnel field-effect transistor (TFET). The proposed device employs a lateral dual source with a vertical drain extension on top of T-shaped channel region. This enables the modification of screening length ( \lambda ) by varying the silicon film ( {t}_{\textsf {Si},\textsf {v}} ) and the oxide ( {t}_{\textsf {Si},\textsf {v}} ) thicknesses at the channel-drain junction to overcome the limitations of high ambipolar leakage in the conventional double-gate TFET (DG-TFET). A 2-D calibrated simulation study has revealed the doubling of on-current ( {I}_{ \mathrm{\scriptscriptstyle ON}} ) and significantly suppressed ambipolar leakage ( {I}_{\textsf {AMB}} ) in the proposed device as compared to the conventional DG-TFET. Furthermore, a five orders of magnitude improvement in {I}_{ \mathrm{\scriptscriptstyle ON}}/{I}_{ \mathrm{\scriptscriptstyle OFF}} , 73% increase in transconductance ( {g}_{\textsf {m}} ), 62% increase in cutoff frequency ( {f}_{\textsf {T}} ), 72% increase in gain-bandwidth product, and 54% improvement in fall propagation delay ( {t}_{\textsf {pHL}} ) are achieved in the proposed device.