Extendibility of CuMn Alloy-Seed Interconnects and the Fundamentals

Abstract

Cu(Mn) alloy seed BEOL studies revealed fundamental insights into Mn segregation and EM enhancement. A metallic-state Mn-rich Cu layer was under the MnOx layer at the Cu/SiCNH cap interface, and was correlated this metallic layer with additional EM enhancement. A carbonyl-based CVD-Co liner film consumed Mn, reducing its segregation and EM benefit, suggesting O-free Co liner films are strategic for Cu-alloy seed extendibility.