Method of forming ultra thin gate dielectric for high performance semiconductor devices

Abstract

The present invention is directed to a semiconductor device having an ultra thin, reliable gate dielectric and a method for making same. In one illustrative embodiment, the present method comprises forming a first layer of nitrogen doped silicon dioxide above a semiconducting substrate, reducing the thickness of the first layer, forming a second layer comprised of a material having a dielectric constant greater than seven above the first layer of silicon dioxide. The method further comprises forming a third layer comprised of a gate conductor material above the second layer, and patterning the first, second and third layers to define a gate conductor and a composite gate dielectric comprised of the first and second layers, and forming at least one source/drain region. The semiconductor device has a composite gate dielectric comprised of a first process layer comprised of a nitrogen doped oxide and a second process layer comprised of a material having a dielectric constant greater than seven. The device further comprises a gate conductor positioned above the composite gate dielectric, and at least one source/drain region formed in the substrate.