Abstract: A semiconductor structure comprising two gate stacks of equal height but different composition. The two gate stacks each comprise two layers, with the first layer of each gate stack comprising the same material and the second layer of each gate stack comprising a different material. Each gate stack has an upper surface a distance `X` above the upper planar surface of a substrate of the semiconductor structure. Thus, the two gate stacks of different composition are of identical height.

Abstract: Fabrication methods and resultant semiconductor structures wherein stack structures are selectively insulated from an enveloping layer of local interconnect material. The fabrication methods involve forming an overpass insulator(s) simultaneously with the underlying gate. Specifically, a layer of non-erodible insulating material is deposited over a layer of conductive material roughly in the area to comprise the stack structure. A simultaneous etch is then performed, and the resultant insulator portion is self-aligned to the underlying conductive material. The insulator portion insulates the stack from a subsequently deposited and planarized layer of local interconnect. Further processing options include decoupling silicide formation on selected stack structures, and various planarization and etching approaches for different available technologies. Specific details of the fabrication methods and resultant structures are set forth.