Comparison of raised source/drain versus raised extension in ultra-thin body, fully-depleted-SOI, including effects of BEOL via capacitances

Raised source/drain (S/D) or raised extension in fully-depleted-SOI (FDSOI) is necessary to boost saturation current, because of increased resistance from the very thin film. We demonstrate that the choice of raising the extension versus the S/D, will depend upon the maximum achievable mobility in the structure at a 60 nm physical gate length. We also study the effects of minimum BEOL via spacing on performance, and its consequence on choosing a raised extension or S/D.