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

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 I–V characteristics, subthreshold swing ( SS ), ON/OFF current ratio ( <tex-math> I_ on/I_ off</tex-math> ), 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 <tex-math>I_ on/I_ off</tex-math> of ∼10 11 and a sub-60-mV/dec SS , and the p-IFETs yield extremely low SS 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.