Impact-Ionization and Tunneling FET Characteristics of Dual-Functional Devices With Partially Covered Intrinsic Regions

Abstract

Dual-functional devices based on gated p-i-n diodes are proposed in this simulation study. The dual-functional devices function not only as n-channel tunneling field-effect transistors (n-TFETs) but also as p-channel impact-ionization FETs (p-IFETs), depending on the bias conditions. In this study, the <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">I–V</i> characteristics, subthreshold swing ( <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">SS</i> ), ON/OFF current ratio ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math> $I_{{\rm on}}/I_{{\rm off}}$</tex-math></inline-formula> ), and band diagram are analyzed using a device simulator (Silvaco Atlas), and the features of the n-TFETs and the p-IFETs are extracted from the simulated data. The n-TFETs exhibit high <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math>$I_{{\rm on}}/I_{{\rm off}} $</tex-math></inline-formula> of ∼10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">11</sup> and a sub-60-mV/dec <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">SS</i> , and the p-IFETs yield extremely low <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">SS</i> of as small as 8.57 mV/dec. Our approach is one of the useful methods to design multifunctional electronics for lowering the power consumption.