Patent ID: 7709396

Claim:
A method of forming patterned features on a substrate, the method comprising: forming a sacrificial structural layer of a core material on the substrate; forming a protective layer of a protective material on the sacrificial structural layer; patterning the sacrificial structural layer and the protective layer to form patterned structures and regions of exposed substrate, the patterned structures including at least two narrow patterned structures having a first linewidth and a first spacing and at least one wide patterned structure having a second linewidth which is greater than the first linewidth, the narrow and wide patterned structures each comprising a layer of the protective material over a layer of the core material; etching the protective material such that the protective material is substantially removed from the at least two narrow patterned structures (leaving behind at least two narrow cores) and a portion of the protective material remains on the at least one wide patterned structure (leaving behind a protective portion on a wide core); forming a conformal layer of a spacer material over the remaining structures and exposed substrate; anisotropically etching the conformal layer to expose the at least two narrow cores and regions of exposed substrate; and removing the at least two narrow cores.