Environmental effects on interfacial adhesion

The effects of temperature and moisture on the reliability of interfaces co mmonly found in thin-film interconnect structures were investigated. Debond growth rate vs. debond driving energy curves (V-G curves) were collected o ver a range of environmental conditions for both metal/SiO2 and polymer/SiO 2 interfaces. For the metal/SiO2 system, the V-G curves were found to be re latively insensitive to increases in temperature over the range of 0 - 85 d egreesC but strongly influenced by the moisture content in the surrounding environment. The exact behavior in the metal/SiO2 system depended on the de bond path and the structure of the thin film stack. The controlling mechani sm for debond advance was found to change as the overall stack structure wa s altered. The polymer/SiO2 system was found to show the same sensitivity t o moisture as the metal/SiO2 system indicating a similar mechanism was lead ing to debond advance. The mechanisms identified in both systems are explai ned in terms of the salient chemical reactions occurring at the debond tip. The relationship between the work of adhesion, or bond breaking process, a nd the macroscopic work of fracture, which includes non-linear energy absor bing processes such as plasticity, was explored. (C) 2001 Elsevier Science Ltd. All rights reserved.