Investigation of Si1-xGeₓ nanosheet TFET performance and single-event transients through germanium mole fractions

Abstract

This paper presents a novel vertically stacked SiGe nanosheet Tunnel Field-Effect Transistor (SiGe NS-TFET) structure in which the channel region is engineered with a Si 1-x Geₓ compound material to improve the device electrical performance. The electrical performance of the device (SiGe NSTFET) is investigated for different germanium (“Ge”) mole fractions using 3D TCAD numerical simulations. The performance metrics such as ON current (I ON ), OFF current (I OFF ), threshold voltage (V TH ), subthreshold swing (SS), transconductance (g m ), and unity cutoff frequency (f T ) are extracted for various “Ge” mole fractions. It is observed that raising the “Ge” mole fraction significantly enhances the band-to-band tunneling probability due to the reduction in bandgap energy, which improves on-state current (I ON ) and transconductance (g m ) and f T performance. Furthermore, the single-event transient (SET) has been analyzed for the Si 1-x Geₓ NSTFET device by adding different-range “Ge” mole fractions. Hence, we have selected seven locations for the radiation strike in this experiment to identify the device's sensitive region. The drain extension area (L6) is found to be the most susceptible region for a normal incidence at a LET (i.e., linear energy transfer) of 10 MeV/mg/cm 2 .