METHOD FOR REDUCING CRITICAL DIMENSIONS USING MULTIPLE MASKING STEPS

摘要

A method for forming features in an etch layer is provided. A first mask is formed over the etch layer wherein the first mask defines a plurality of spaces with widths. A sidewall layer is formed over the first mask. Features are etched into the etch layer through the sidewall layer, wherein the features have widths that are smaller than the widths of the spaces defined by the first mask. The mask and sidewall layer are removed. An additional mask is formed over the etch layer wherein the additional mask defines a plurality of spaces with widths. A sidewall layer is formed over the additional mask. Features are etched into the etch layer through the sidewall layer, wherein the widths that are smaller than the widths of the spaces defined by the first mask. The mask and sidewall layer are removed.