Study of Random Dopant Fluctuation (RDF) Effects for the Tri-Gate Bulk MOSFET
Changhwan Shin and Tsu-Jae King Liu
The Korea Foundation for Advanced Studies
A study of random dopant fluctuation (RDF) effects on the tri-gate bulk MOSFET vs. the planar bulk MOSFET is performed via atomistic three-dimensional device simulation, for devices with 20 nm gate length. For identical nominal body and source/drain doping profiles and layout width, the tri-gate bulk MOSFET shows less threshold voltage (VTH) lowering and variation. RDF effects are found to be caused primarily by body RDF. The tri-gate bulk MOSFET offers a new method of VTH adjustment, via tuning of the retrograde body doping depth, to mitigate tradeoffs in VTH variation and short-channel effect control.