Effect of Plasma Treatments on the Interface Chemistry and Adhesion Strength Between Cu Metallization and SiCN Etch Stop Layer

Abstract

In this study, the interface chemistry and adhesion strengths between Cu and SiCN etch stop layers have been investigated under different plasma treatments. From the examination of interface microstructures and the analyses of chemical compositions and bonding configurations, an oxide layer was found to exist at the untreated interface. After and treatments, the amount of oxides was effectively reduced. Some Cu silicides formed during SiCN deposition, and Cu nitrides even formed under plasma treatment. The adhesion strengths of the interfaces were measured by nanoindentation and nanoscratch tests under which interface delamination occurred around indented regions. The adhesion energy of the untreated interface was obtained as about 4.98 and , respectively, by nanoindentation and nanoscratch tests. After and plasma treatments, the adhesion energy was effectively improved to 5.90 and by nanoindentation test, and to 1.74 and by nanoscratch test, respectively, because of the removing of oxides and the formation of Cu silicides and nitrides at the interfaces.