Scaling the bulk-driven MOSFET

Abstract

This paper investigates the impact of device scaling on the bulk-driven MOSFET. In particular, the behavior of gmb is observed across process technology and it is shown that the gmb/gm ratio falls from 0.38 to 0.12 between IBM's 0.25 μm and 65 nm bulk CMOS processes via simulation. Delta and step doping are then proposed to enable the scaling of bulk-driven MOSFETs down to a channel length of 80 nm on a one volt supply. Using 2-D device simulations in ATLAS, it is shown that the intrinsic gain of a bulk-driven MOSFET can be enhanced by as much as 78% for a step doping profile and 106% for a delta doping profile in an NMOS device when compared to a uniform substrate.