Multi-height and multi-width interconnect line metallization for integrated circuit structures

Abstract

Integrated circuit metallization lines having a planar top surface but different vertical heights, for example to control intra-layer resistance/capacitance of integrated circuit interconnect. A hardmask material layer may be inserted between two thicknesses of dielectric material that are over a via metallization. Following deposition of the hardmask material layer, trench openings may be patterned through the hardmask layer to define where line metallization will have a greater height. Following the deposition of a thickness of dielectric material over the hardmask material layer, a trench pattern may be etched through the uppermost thickness of dielectric material, exposing the hardmask material layer wherever the trench does not coincide with an opening in the hardmask material layer. The trench etch may be retarded where the hardmask material layer is exposed, resulting to trenches of differing depth. Trenches of differing depth may be filled with metallization and then planarized.