Hetero-Gate-Dielectric Tunneling Field-Effect Transistors

Abstract

A tunneling field-effect transistor (TFET) is considered one of the most promising alternatives to a metal–oxide–semiconductor field-effect transistor due to its immunity to short-channel effects. However, TFETs have suffered from low <emphasis emphasistype="smcaps" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">on</emphasis> -current, severe ambipolar behavior, and gradual transition between <emphasis emphasistype="smcaps" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">on</emphasis> - and <emphasis emphasistype="smcaps" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">off </emphasis> -states. To address those issues, the authors have proposed hetero-gate-dielectric TFETs. The proposed device enhances <emphasis emphasistype="smcaps" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">on</emphasis> -current, suppresses ambipolar behavior, and makes abrupt <emphasis emphasistype="smcaps" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">on</emphasis> – <emphasis emphasistype="smcaps" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">off</emphasis> transition by replacing the source-side gate insulator with a high- <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$k$</tex> </formula> material, which induces a local minimum of the conduction band edge at the tunneling junction.