Adhesion and debonding of multi-layer thin film structures

Abstract

A fracture mechanics technique to quantitatively measure the adhesion or interfacial fracture resistance of interfaces in thin film structures is described. Adhesion values obtained for the technologically important SiO2/TiN interface in microelectronic interconnect structures are related to a range of material, mechanical and design parameters which include interface morphology and adjacent ductile layer thickness. In addition, the interface was shown to be susceptible to environmentally-assisted subcritical debonding similar to stress corrosion cracking of SiO2 glass in moist air environments. Subcritical debonding behavior was sensitive to a range of material and design parameters, and is expected to have important implications for long term device reliability.