Patent ID: 8237233
Filing Date: 2012-08-07
Classification: H01L

Abstract:
1. A field effect transistor comprising: a substrate; a semiconductor body on said substrate, said semiconductor body comprising a channel region with a sidewall, a center portion and an edge portion between said sidewall and said center portion; an isolation region on said substrate positioned laterally adjacent to said sidewall; and a gate structure traversing a width of said channel region over said center portion and said edge portion and further extending laterally beyond said sidewall onto said isolation region, said gate structure comprising a first section above said center portion and a second section above said edge portion and said sidewall, said first section having a single gate dielectric layer above and immediately adjacent to said center portion and further having a first gate conductor layer above and immediately adjacent to said single gate dielectric layer, said second section having multiple stacked gate dielectric layers above and immediately adjacent to said edge portion and extending laterally over said sidewall, said multiple stacked gate dielectric layers comprising an upper gate dielectric layer further extending laterally onto a top surface of said first gate conductor layer, said second section further having a portion of a second gate conductor layer above and immediately adjacent to said multiple stacked gate dielectric layer such that said first section has a first effective work-function and said second section has a second effective work function that is different from said first effective work-function, and at least one of said first gate conductor layer and said second gate conductor layer comprising a metal.