Patent ID: 7365378

Claim:
A field effect transistor comprising: a substrate comprising source/drain extensions positioned laterally adjacent a channel region; a gate oxide layer on said channel region and overlapping portions of said source/drain extensions; a gate conductor on said gate oxide layer and comprising a sidewall perpendicular to said substrate; and a sidewall spacer directly on said substrate positioned laterally adjacent said sidewall and said gate oxide layer, wherein said sidewall spacer comprises: a gap on a corresponding one of said source/drain extensions and positioned laterally adjacent said sidewall and said gate oxide layer, wherein said gap comprises a permittivity value of one; and a permeable low-K dielectric layer on said corresponding one of said source/drain extensions, positioned laterally adjacent said gap, and further positioned above said gap extending towards said sidewall, wherein said permeable low-K dielectric layer comprises a permittivity value of less than three.