Patent ID: 8450834

Claim:
A field effect transistor comprising: a substrate; a gate structure comprising a sidewall overlying the substrate; a silicide region in the substrate on one side of the gate structure having an inner edge closest to the gate structure; a first oxygen-sealing layer adjoining the sidewall of the gate structure; an oxygen-containing layer adjoining the first oxygen-sealing layer on the sidewall and further comprising a portion extending over the substrate, wherein an outer edge of the oxygen-containing layer is in contact with the inner edge of the silicide region; a second oxygen-sealing layer adjoining the oxygen-containing layer and extending over the portion of the oxygen-containing layer over the substrate, wherein an outer edge of the second oxygen-sealing layer is offset from the inner edge of the silicide region; and a liner oxide adjoining the second oxygen-sealing layer and extending over the silicide region, wherein a top portion furthest from the substrate of the liner oxide and a top portion furthest from the substrate of the second oxygen-sealing layer are substantially co-planar.