Hybrid beol metallization utilizing selective reflection mask

Abstract

A method for fabricating semiconductor wafers comprises creating a semiconductor wafer having a plurality of wide copper wires and a plurality of narrow copper wires embedded in a dielectric insulator. The width of each wide copper wire is greater than a cutoff value and each narrow copper is less than the cutoff value. An optical pass through layer is deposited over a top surface of the wafer and a photo-resist layer is deposited over the optical pass through layer. The wafer is exposed to a light source to selectively remove photo-resist, forming a self-aligned pattern where photo-resist only remains in areas above wide copper wires. The self-aligned pattern is transferred to the optical pass through layer and the remaining photo-resist is removed. The wafer is chemically etched to remove the narrow copper wires, defining narrow gaps in the dielectric insulator. The wafer is metallized with non-copper metal, forming narrow non-copper metal wires.

Dependencies are inferred from the claim text.