A method for forming nanowires includes forming a plurality of epitaxial layers on a substrate, the layers including alternating material layers with high and low Ge concentration and patterning the plurality of layers to form fins. The fins are etched to form recesses in low Ge concentration layers to form pillars between high Ge concentration layers. The pillars are converted to dielectric pillars. A conformal material is formed in the recesses and on the dielectric pillars. The high Ge concentration layers are condensed to form hexagonal Ge wires with (111) facets. The (111) facets are exposed to form nanowires.