Nano-wires, preferably of less than 20 nm diameter, can be formed with minimized risk of narrowing and breaking that results from silicon atom migration during an annealing process step. This is accomplished by masking portion of the active layer where silicon atomer would otherwise agglomerate with a material such as silicon dioxide, silicon nitride, or other dielectric that eliminates or substantially reduces the silicon atom migration. Nano-wires, nanotubes, nano-rods, and other features can be formed and can optionally be incorporated into devices, such as by use as a channel region in a transistor device.