A self-align patterning method for forming patterns may include forming a first layer on a substrate, and forming a plurality of first hard mask patterns on the first layer. A sacrificial layer is formed on top surfaces and sidewalls of the first hard mask patterns, thereby forming a gap between respective facing portions of the sacrificial layer on the sidewalls of the first hard mask patterns. A second hard mask pattern is formed in the gap, the sacrificial layer is etched using the second hard mask pattern as a mask to expose the first hard mask patterns, the first layer is exposed using the exposed first hard mask patterns and the second hard mask pattern. The exposed first layer is then etched using the first and second hard mask patterns.
Such self-aligned patterning methods are discussed, for example, in U.S. Pat. No. 7,615,496 to Lee et al., entitled “Method of Forming Pad Patterns Using Self-Aligned Double Patterning Method, Pad Pattern Layout Formed Using the Same, And Method Of Forming Contact Holes Using Self-Aligned Double Patterning Method,” the disclosure of which is hereby incorporated herein in its entirety by reference.
USPTO Backgrounds
USPTO Backgrounds