Methods of forming an air gap adjacent a gate of a transistor and a gate contact above the active region of the transistor

Abstract

One method includes performing an etching process to define a gate cavity that exposes an upper surface and at least a portion of the sidewalls of a gate structure and forming a replacement spacer structure adjacent the exposed sidewalls of the gate structure, wherein the replacement spacer structure exposes a portion of the upper surface of the gate structure and includes at least one air space. In this example, the method also includes forming a conformal etch stop layer and a replacement gate cap structure in the gate cavity, selectively removing a portion of the replacement gate cap structure and a portion of the conformal etch stop layer so as to thereby expose the upper surface of the gate structure, and forming a conductive gate contact structure (CB) in the conductive gate contact opening, wherein the entire conductive gate contact structure (CB) is positioned vertically above the active region.