Silicon and Silicon Germanium Terahertz Electronics

Silicon and silicon germanium transistors with feature sizes below 100 nm have demonstrated operation in sub-terahertz and terahertz frequency ranges with potential applications in communications, Beyond 5 G WI FI, sensing, and imaging. New features of ballistic electron transport in deep submicron devices must be accounted for design, modeling, and characterization of Si and SiGe transistors operating at sub-THz and THz frequencies. The key issue is the crucial role that the electron inertia and electron viscosity play at ultra-short sizes determining the frequency and decay of the plasma waves - the electron density oscillations in the transistor channel electronic (or hole) fluid. This paper will present a review of the state-of-the art of the Si and SiGe THz electronics and will focus on Si plasmonic devices emerging as key competitors for THz and sub-THz applications.