The present disclosure provides methods of forming patterning features in a semiconductor structure using a sidewall image transfer technique. The method includes first forming a plurality of sacrificial mandrels over a dielectric hard mask layer. Each sacrificial mandrel has a width greater than a minimum spacing between adjacent patterning features subsequently formed according to a circuit design. After forming a plurality of spacer material layer portions on sidewalls of the sacrificial mandrels, a plurality of filler material layer portions are formed adjacent the spacer material layer portions. The cycle of forming the spacer material layer portions and filler material layer portions may be repeated until spaces between sacrificial mandrels are completely filled. Removal of the sacrificial mandrels and the filler material layer portions provides patterning features.