InGaAs/InP Tunnel FETs With a Subthreshold Swing of 93 mV/dec and $I_{\rm ON}/I_{\rm OFF}$ Ratio Near $\hbox{10}^{6}$

Abstract

Vertical n-channel tunnel field-effect transistors (TFETs) with tunneling normal to the gate based on an n+ In <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">∞=0.53-&gt;;1</sub> GaAs/p <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">+</sup> InP heterojunction have been demonstrated to exhibit simultaneously a high 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> ratio of 6 × 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">5</sup> , a minimum subthreshold swing (SS) of 93 mV/dec, and an on-current of 20 μA/μm at V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">DS</sub> = 0.5 V and a gate swing of 1.75 V at 300 K, a record TFET performance. The significant improvement in device performance is ascribed to the adoption of a thin equivalent oxide thickness (EOT) of ~1.3 nm for improved electrostatics and the use of plasma-enhanced chemical vapor deposition SiN <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">∞</sub> mesa passivation to preserve the integrity of the thin exposed semiconductor layers.