Disclosed are approaches for forming a semiconductor device. In some embodiments, a method may include providing a patterned hardmask over a substrate, and providing, from an ion source, a plasma treatment to a first section of the patterned hardmask, wherein a second section of the patterned hardmask does not receive the plasma treatment. The method may further include etching the substrate to form a plurality of fins in the substrate, wherein the first section of the patterned hardmask is etched faster than the second section of the patterned hardmask.