A method for manufacturing a semiconductor device includes forming a stacked configuration of a plurality of silicon germanium layers and a plurality of silicon layers on a semiconductor substrate, wherein the stacked configuration comprises a repeating arrangement of a silicon layer stacked on a silicon germanium layer, patterning the stacked configuration into a plurality of patterned stacks spaced apart from each other, and etching exposed sides of the plurality of silicon germanium layers to remove portions of the silicon germanium layers from lateral sides of each of the plurality of silicon germanium layers, wherein a concentration of germanium is varied between each of the plurality of silicon germanium layers to compensate for variations in etching rates between the plurality of silicon germanium layers to result in remaining portions of each of the plurality of silicon germanium layers having the same or substantially the same width as each other.