Impact ionization nanowire transistor with multiple-gates, silicon-germanium impact ionization region, and sub-5 mV/decade subtheshold swing

Abstract

We report the first demonstration of an Impact Ionization Nanowire Multiple-gate Field-Effect Transistor (I-MuGFET or I-FinFET). Excellent subthreshold swing of sub-5 mV/decade at room temperature was achieved. The multiple-gate structure enhances the impact ionization rate in the fin or nanowire channel, reduces the breakdown voltage and improves device performance. A Silicon-Germanium (SiGe) Impact Ionization Region (I-Region) is integrated on a Si or SiGe nanowire to enhance performance and reduce the breakdown voltage. A record low breakdown voltage of -4.75 V is achieved for SiGe nanowire device. Complementary pair of I-FinFETs were realized. The lower electron and hole impact-ionization threshold energy of SiGe greatly enhances the drive current of n- and p-channel devices by 3 and 2.4 folds, respectively. © 2007 IEEE.