Analog performance of the nanoscale double-gate metal-oxide-semiconductor field-effect-transistor near the ultimate scaling limits

Abstract

We explore the prospective behavior of the nanoscale double-gate metal-oxide-semiconductor field-effect-transistor (DG-MOSFET) when used as the basis for building analog circuits. Results for transconductance, output conductance, and related parameters, such as transconductance efficiency, and Early voltage, are presented in the ballistic and diffusive regimes using the non-equilibrium Green’s function method (NEGF) and the scattering theory of the nanoscale MOSFET. Very high transconductance (∼20mS∕μm), approaching the ballistic limit, can be achieved provided that technological improvements further increase the electron mobility in the silicon film. For the ballistic limit a cutoff frequency of about 1–4THz is possible. The transconductance efficiency is not to much affected by length scaling and temperature. The output conductance and Early voltage are severely affected by length scaling as channel length-modulation (CLM) and drain-induced barrier lowering (DIBL) effects become more important, but they are acceptable for channel lengths above 15nm. Finally, it is shown that the International Technology Roadmap requirements for small-signal parameters, in mixed-signals systems, near the ultimate scaling limit, could be accomplished using the DG-MOSFET.