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 (nTFETs) 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 (I_on/I_off), 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 I_on/I_off of ~10¹¹ 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.