Negative capacitance as a performance booster for tunnel FET

Abstract

We have investigated a super steep subthreshold slope tunnel FET by introducing negative capacitance of a ferroelectric HfO <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> gate insulator, for the first time. The simulation study revealed that the electric field at the tunnel junction of the tunnel FET can be effectively enhanced by potential amplification due to the negative capacitance. The enhanced electric field increases the band-to-band tunneling rate and I <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">on</inf> /I <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">off</inf> ratio, which results in 10× higher energy efficiency than in tunnel FET.