Patent ID: 7902576

Claim:
A transistor, comprising: a semiconductor substrate, at least some of which is treated to include carbon; a gate structure formed over the semiconductor substrate and defining a channel therebelow in the semiconductor substrate; source and drain regions formed within the semiconductor substrate on opposing sides of the channel, the source and drain regions formed with a phosphorus dopant, wherein the source and drain regions are located in regions of the semiconductor substrate that include carbon and the channel region is located in a region of the semiconductor substrate that is not treated to include carbon, the surface of the source and drain regions being planar with the surface of the semiconductor substrate, wherein the regions of the semiconductor substrate that include carbon do not extend under the gate structure; source and drain extension regions formed in the semiconductor substrate on opposing sides of the channel, the source and drain extension regions formed with a phosphorous dopant and extending into the channel further than the source and drain regions; and offset spacers formed adjacent to the gate structure, wherein the source and drain extension regions are substantially aligned with the offset spacers, and wherein regions of the substrate substantially aligned with the offset spacers include carbon.