Abstract: A method of forming a semiconductor structure includes forming a metal gate stack over a shallow trench isolation (STI) material in a semiconductor substrate, forming an interlayer dielectric over the STI material, recessing the interlayer dielectric to a height lower than a top surface of the metal gate stack, forming a helmet structure over the recessed interlayer dielectric, and after forming the helmet structure, etching the metal gate stack until reaching the STI material.

Abstract: A method includes providing a structure having a substrate, semiconductor fins, and an isolation structure between adjacent semiconductor fins; forming a first gate structure engaging the semiconductor fins; depositing an inter-layer dielectric layer over the semiconductor fins and the first gate structure; removing the first gate structure, resulting in a first trench; depositing a second gate structure into the first trench, wherein the second gate structure includes a dielectric layer and a conductive layer; forming one or more mask layers over the second gate structure; patterning the one or more mask layers to have an opening exposing a portion of the second gate structure between two adjacent semiconductor fins; and etching the second gate structure through the opening to produce a second trench having tapered sidewalls, wherein the second trench is wider at top than at bottom.

Abstract: A semiconductor device includes a substrate, first and second fins protruding out of the substrate, and first and second high-k metal gates (HK MG) disposed over the first and second fins, respectively. From a top view, the first and second fins are arranged lengthwise along a first direction, the first and second HK MG are arranged lengthwise along a second direction generally perpendicular to the first direction, and the first and second HK MG are aligned along the second direction. In a cross-sectional view cut along the second direction, the first HK MG has a first sidewall that is slanted from top to bottom towards the second HK MG, and the second HK MG has a second sidewall that is slanted from top to bottom towards the first HK MG. Methods for producing the semiconductor device are also disclosed.