Abstract: In one example, the method disclosed herein includes forming a fin comprised of a semiconducting material, wherein the fin has a first, as-formed cross-sectional configuration, forming a sacrificial gate structure above the fin, forming sidewall spacers adjacent at least a portion of the sacrificial gate structure and removing the sacrificial gate structure to thereby define a gate cavity that exposes a portion of the fin. The method also includes the steps of performing a fin reflow process on the exposed portions of the fin to define a nanowire structure having a cross-sectional configuration that is different from the first cross-sectional configuration and forming a replacement gate structure in the gate cavity and at least partially around the nanowire structure.

Abstract: One illustrative method disclosed herein includes removing a portion of a sacrificial sidewall spacer to thereby expose at least a portion of the sidewalls of a sacrificial gate electrode and forming a liner layer on the exposed sidewalls of the sacrificial gate electrode. In this example, the method also includes forming a sacrificial gap fill material above the liner layer, exposing and removing the sacrificial gate electrode to thereby define a gate cavity that is laterally defined by the liner layer, forming a replacement gate structure, removing the sacrificial gap fill material and forming a low-k sidewall spacer adjacent the liner layer. A device is also disclosed that includes a gate cap layer, a layer of silicon nitride or silicon oxynitride positioned on each of two upstanding portions of a gate insulation layer and a low-k sidewall spacer positioned on the layer of silicon nitride or silicon oxynitride.