METHODS FOR MULTI-STEP COPPER PLATING ON A CONTINUOUS RUTHENIUM FILM IN RECESSED FEATURES

摘要

Methods are provided for multi-step Cu metal plating on a continuous Ru metal film (214) in recessed features (206, 207, 208, 209, 211, 213, 264, 275a, 275b) found in advanced integrated circuits. The use of a continuous Ru metal film (214) prevents formation of undesirable micro-voids during Cu metal filling of high-aspect-ratio recessed features (206, 207, 208, 209, 264, 275a, 275b), such as trenches (266) and vias (268), and enables formation of large Cu metal grains (233) that include a continuous Cu metal layer (228) plated onto the continuous Ru metal film (214). The large Cu grains (233) lower the electrical resistivity of the Cu filled recessed features (206, 207, 208, 209, 211, 213, 275a, 275b) and increase the reliability of the integrated circuit.