Source/drain extension scaling for 0.1 /spl mu/m and below channel length MOSFETs

In this paper, we investigate the scaling of source/drain extension (SDE) depth and SDE to gate overlap for 0.1 /spl mu/m and below MOSFETs. We show for the first time that a minimum SDE to gate overlap of 15-20 nm is needed to prevent drive current (I/sub DSAT/) degradation. We also show for the first time that scaling SDE vertical depths below 30-40 nm results in little to no performance benefit for 0.1 /spl mu/m devices and beyond since any improvement in short channel effects due to reduced charge sharing is offset by a large increase in external resistance and poor gate coupling between the channel and extensions.