Methods of forming a masking pattern for integrated circuits

摘要

In some embodiments, methods for forming a masking pattern for an integrated circuit are disclosed. In one embodiment, mandrels defining a first pattern are formed in a first masking layer over a target layer. A second masking layer is deposited to at least partially fill spaces of the first pattern. Sacrificial structures are formed between the mandrels and the second masking layer. After depositing the second masking layer and forming the sacrificial structures, the sacrificial structures are removed to define gaps between the mandrels and the second masking layer, thereby defining a second pattern. The second pattern includes at least parts of the mandrels and intervening mask features alternating with the mandrels. The second pattern may be transferred into the target layer. In some embodiments, the method allows the formation of features having a high density and a small pitch while also allowing the formation of features having various shapes and sizes.

主权项

1. A method for integrated circuit fabrication, the method comprising:
forming mandrels comprising mandrel material over a substrate, the mandrels separated by spaces; depositing a filler material into the spaces; forming sacrificial structures along an interface between the mandrels and the filler material; removing the sacrificial structures to define a mask comprising open spaces delineated by mask features formed of the mandrel material and the filler material, wherein portions of the mask features at least partially block openings to the open spaces; subjecting the mask features to an etch to remove the portions of the mask features at least partially blocking the openings; and subsequently transferring a pattern derived from the mask features to the substrate.