Resistivity of copper interconnects at 28 nm pitch and copper cross-sectional area below 100 nm2

The resistivity of damascene Cu is measured at cross-sectional area as low as 95 nm ² . The impact of aspect ratio and line edge roughness on resistivity is investigated. Kelvin resistance test structures are demonstrated with 28 nm pitch wires patterned by directed self-assembly of lamellar block copolymers. The effective resistivity of TaN/Ta/Cu wires is compared with alternative metals.