Selective epitaxy of a semiconductor material is performed on a semiconductor fin to form a semiconductor nanowire. Surfaces of the semiconductor nanowire include facets that are non-horizontal and non-vertical. A gate electrode can be formed over the semiconductor nanowire such that the faceted surfaces can be employed as channel surfaces. The epitaxially deposited portions of the faceted semiconductor nanowire can apply stress to the channels. Further, an additional semiconductor material may be added to form an outer shell of the faceted semiconductor nanowire prior to forming a gate electrode thereupon. The faceted surfaces of the semiconductor nanowire provide well-defined charge carrier transport properties, which can be advantageously employed to provide a semiconductor device with well-controlled device characteristics.