Methods for Controlling Line Dimensions in Spacer Alignment Double Patterning Semiconductor Processing

摘要

Methods for forming uniformly spaced and uniformly shaped fine lines in semiconductor processes using double patterning. Dummy lines are formed over a substrate. Sidewall spacer material is deposited over the top and sides of each of the dummy lines. Etching is performed to remove the top surface sidewall spacer material from the tops of the dummy lines. The dummy material is removed by selective etching leaving the spacer material. A photolithographic mask is formed defining inner lines that are desired for a substrate etching step, and temporary lines outside of the desired lines. The temporary lines are partially masked. The temporary lines are partially removed while the inner desired lines are retained. A transfer etch process then patterns an underlying mask layer corresponding to the inner desired lines, and the mask layer is used for etching lines in an underlying semiconductor substrate.