Chemoepitaxy-based directed self assembly process with tone inversion for unidirectional wiring

Abstract

After forming a material stack including, from bottom to top, a dielectric material layer, a transfer layer, a hard mask layer and a neutral layer over a substrate, the neutral layer and the hard mask layer is patterned to create trenches therein that correspond to areas where unnecessary lines generated by a self-assembly of a self-assembling material subsequently formed and/or unnecessary portions of such lines are present. The self-assembling material is applied over the top surfaces of the patterned neutral layer and the transfer layer to form a self-aligned lamellar structure including alternating first and second domains. The second domains are removed selective to the first domains to provide a directed self-assembly (DSA) pattern of the first domains. Portions of the first domains not intersecting the trenches can be transferred into the patterned hard mask layer, resulting in a composite pattern of a pattern of trenches and the DSA pattern.