Patent ID: 6891231

Claim:
A field effect transistor comprising: a substrate comprising a source region, a drain region, and a channel region therebetween; an insulating layer being disposed over said channel region, said insulating layer comprising at least one member selected from the group consisting of Al 2 O 3 , HfO 2 , ZrO 2 , TiO 2 , La 2 O 3 , Y 2 O 3 , Gd 2 O 3 , Ta 2 O 5 , silicates thereof and aluminates thereof; a barrier layer having a thickness in a range from about 5 Å to 10 Å, and comprising a plurality of adjacent layers formed on said insulating layer, said barrier layer comprising at least one member selected from the group consisting of aluminum oxynitride, aluminum nitride and silicon nitride; and a polysilicon gate electrode formed on said barrier layer, said barrier layer inhibiting a diffusion of dopants from said polysilicon gate electrode to said insulating layer.