Fracture of Thin Film Structures With Creeping Underlayer

Fracture in small structures has been studied intensely in recent years, motivated by diverse applications such as interconnects in mircoprocessors, resonant structures in microelectromehanical systems, thermal barrier coatings in gasturbine engines, and multilayers in medical implants. The applications typically require that materials with extremely different properties be integrated in small dimensions. The structural complexity, as well as the small feature sizes, can lead to unusual phenomena. For example, it is discovered that cracks can grow in brittle films under cyclic temperatures, driven by ratcheting plastic deformation in a metal underlayer. We will revisit this phenomenon toward the end of this paper.Copyright © 2003 by ASME