A method of forming a nanowire device includes forming semiconductor material layers above a semiconductor substrate, forming a gate structure above the semiconductor material layers, forming a first sidewall spacer adjacent to the gate structure and forming a second sidewall spacer adjacent to the first sidewall spacer. The method further includes patterning the semiconductor material layers such that each layer has first and second exposed end surfaces. The gate structure, the first sidewall spacer, and the second sidewall spacer are used in combination as an etch mask during the patterning process. The method further includes removing the first and second sidewall spacers, thereby exposing at least a portion of the patterned semiconductor material layers. The method further includes forming doped extension regions in at least the exposed portions of the patterned semiconductor material layers after removing the first and second sidewall spacers.