A method of processing a stack, the method including depositing a fusible material on a first hardmask layer, the first hardmask layer disposed on a surface of a pre-processed stack, the pre-processed stack being disposed on at least a portion of a substrate; heating the fusible material layer to a temperature at or above its melting point to cause it to form a fusible material sphere, the fusible material sphere disposed on less than the entire first hardmask layer; etching the first hardmask layer, wherein the fusible material sphere prevents a portion of the first hardmask layer from etching, thereby forming a second hardmask layer; and etching the pre-processed stack, wherein at least the second hardmask layer prevents a portion of the pre-processed stack from etching, thereby forming a stack.