Semiconductor devices employing high-k dielectric layers as a gate insulating layer and methods of fabricating the same

Abstract

A method of fabricating a semiconductor device includes providing a semiconductor substrate having a first region and a second region, forming a nitrogen-containing lower gate insulating layer on the semiconductor substrate, forming an upper gate insulating layer on the nitrogen containing lower gate insulating layer, forming a lower metal layer on the upper gate insulating layer; and selectively removing the lower metal layer in the first region such that a lower metal layer pattern remains in the second region, wherein the upper gate insulating layer in the first region prevents the lower gate insulating layer in the first region from being etched during removing of the lower metal layer in the first region. A semiconductor device fabricated by the method is also provided.