Patent ID: 7999251

Claim:
A field effect transistor (FET) comprising: a back gate comprising a doped semiconductor substrate; a back gate dielectric located on an upper surface of said back gate; a single-crystal semiconductor nanowire composed of an undoped semiconductor material located atop said back gate dielectric, said single-crystal semiconductor nanowire comprising a semiconductor channel, a first undoped semiconductor material portion located on one side of said semiconductor channel, and a second undoped semiconductor material portion located on another side of said semiconductor channel; a dielectric stack having a first contact opening extending to said first undoped semiconductor material portion and a second contact opening extending to said second undoped semiconductor material portion; a source region located in said first contact opening and in contact with said first undoped semiconductor material portion; and a drain region located in said second contact opening and in contact with said second undoped semiconductor material portion, wherein said source and drain regions each comprise a doped epitaxial semiconductor material extending upward from said first and second undoped semiconductor material portions in a radial orientation.