Effects of Post-annealing and Co Interlayer Between SiNx and Cu on the Interfacial Adhesion Energy for Advanced Cu Interconnections

Effects of Co interlayer and 200 °C post-annealing treatment on interfacial adhesion energy of SiN x /Cu structure were systematically investigated. Initial interfacial adhesion energy of SiN x /Cu structure measured by double cantilever beam test was 0.92 J/m 2 . The interfacial adhesion energy increased to 2.94 J/m 2 with Co interlayer between SiN x and Cu films. After post-annealing treatment at 200 °C for 500 h, the interfacial adhesion energy of SiN x /Co/Cu structure decreased to 0.95 J/m 2 . X-ray photoelectron spectroscopy analysis revealed that the interfacial adhesion energy increased for SiN x /Co/Cu thin films due to CoSi 2 reaction layer at SiN x /Co interface, but sharply decreased during post-annealing treatment by SiO 2 formation at SiN x /Co interface. Graphic abstract