Impacts of diameter-dependent annealing on S/D extension random dopant fluctuations in silicon nanowire MOSFETs

In this paper, the impacts of diameter-dependent annealing (DDA) effect on nanowire S/D extension random dopant fluctuations (SDE-RDF) in silicon nanowire MOSFETs (SNWTs) are investigated, in terms of electrostatic properties, source/drain series resistance (RSD), and driving current. The SDE-RDF induced variations of threshold voltage (Vth) and DIBL in SNWTs with different diameters are found to be modest and decrease as the diameters down-scale. However, SDE-RDF induced RSD variation in SNWTs is enhanced by abnormal DDA effects, which aggravates the drive current variations with the downscaling of SNWT diameter. The results also show that Vth is the dominant factor in ON/OFF current ratio variation while RSD dominates that of ON current. The tradeoff between RSD and Vth dominant current variations is discussed to give some guidelines for SDE-RDF-aware design in SNWTs. ?2010 IEEE.EI