Ultrafine dimensions, smaller than conventional lithographic capabilities, are formed employing an efficient inverse spacer technique comprising selectively removing spacers. Embodiments include forming a first mask pattern over a target layer, forming a spacer layer on the upper and side surfaces of the first mask pattern leaving intermediate spaces, depositing a material in the intermediate spacers leaving the spacer layer exposed, selectively removing the spacer layer to form a second mask pattern having openings exposing the target layer, and etching the target layer through the second mask pattern.