Patent ID: 7932556
Filing Date: 2011-04-26
Classification: H01L

Abstract:
1. A field effect transistor (FET), comprising: body regions of a first conductivity type over a semiconductor region of a second conductivity type, the body regions forming p-n junctions with the semiconductor region; source regions of the second conductivity type over the body regions, the source regions forming p-n junctions with the body regions; gate electrodes extending adjacent to but being insulated from the body regions by a gate dielectric; contact openings extending into the body regions between adjacent gate electrodes; a seed layer extending along a bottom of each contact opening, the seed layer serving as a nucleation site for promoting growth of conductive fill material; a conductive fill material filling a lower portion of each contact opening, wherein an upper surface of the conductive fill material is below a bottom surface of the source regions; and an interconnect layer filling an upper portion of each contact opening and being in direct contact with the conductive fill material, the interconnect layer also being in direct contact with corresponding source regions along upper sidewalls of the contact openings.