Compact, Physics-Based Modeling of Nanoscale Limits of Double-Gate MOSFETs

Compact, physics-based models of subthreshold swing and threshold voltage are presented for double-gate (DG) MOSFETs in symmetric, asymmetric, and ground-plane modes. Applying these device models, threshold voltage variations in DG MOSFETs are comprehensively and exhaustively investigated using a unique, scale-length based methodology. Quantum mechanical effects and fringeinduced barrier lowering effect on threshold voltage, caused by ultra-thin silicon film and potential use of highpermittivity gate dielectrics, respectively, have been analytically modeled giving close agreement to numerical simulations. Scaling limits projections indicate that individual DG MOSFETs with good turn-off behavior are feasible at 10 nm scale; however, practical exploitation of these devices toward gigascale integrated systems requires development of novel technologies for significant improvement in process control.