The present invention provides ART techniques with reduced LER. In one aspect, a method of ART with reduced LER is provided which includes the steps of: providing a silicon layer separated from a substrate by a dielectric layer; patterning one or more ART lines in the silicon layer selective to the dielectric layer; contacting the silicon layer with an inert gas at a temperature, pressure and for a duration sufficient to cause re-distribution of silicon along sidewalls of the ART lines patterned in the silicon layer; using the resulting smoothened, patterned silicon layer to pattern ART trenches in the dielectric layer; and epitaxially growing a semiconductor material up from the substrate at the bottom of each of the ART trenches, to form fins in the ART trenches.