Investigation of intrinsic dielectric breakdown mechanism in Cu/low-κ interconnect system

Using a specifically designed test structure applying human body model electrostatic discharge (ESD) stress, the origin of dielectric breakdown in Cu/low-κ interconnect systems was found to be in interfacial delamination. The interfacial delamination between a SiC capping layer and a SiOC interdielectric layer is responsible for the increase of intermetal dielectric leakage current, causing high current Joule heating as well as catastrophic thermal breakdown. Also, the defect density increased as the delamination becomes wider while the number of ESD zaps increases.