Patent ID: 6563151
Filing Date: 2003-05-13
Classification: H01L

Abstract:
A field effect transistor, comprising:a semiconductor substrate having a channel region of first conductivity type therein extending adjacent a surface thereof; source and drain regions of second conductivity type extending in said semiconductor substrate and forming P-N rectifying junctions with the channel region; a buried region of first conductivity that is disposed vertically between the channel region and a bulk portion of said semiconductor substrate and extends continuously in a lateral direction from an underside of said source region to an underside of said drain region, said buried region having a higher first conductivity type dopant concentration therein relative to the channel region and the bulk portion of said semiconductor substrate; a gate electrode extending on the channel region and comprising a first electrically conductive material having a first work function; and a first sub-gate electrode extending on the channel region and comprising a second electrically conductive material having a second work function that is unequal to the first work function.