ABSTRACT
A thin solid film grown on a solid substrate is generally deposited in a state of stress. This stress can be quite large, often exceeding the yield stress of the material in bulk form, and can lead to deleterious effects such as cracking, spalling and de-adhesion. However, it is sometimes necessary, or even desirable, for a thin film to be under stress. For example, it is generally required for electronic material applications that a semiconductor film be grown epitaxially, i.e., as a single crystal deposited on a single crystal substrate with defect-free lattice matching at the filmsubstrate interface. If the in-plane equilibrium lattice spacings of the film and substrate are different, the film will be under stress in order to achieve this lattice matching. Another example where an intrinsic stress is desirable concerns a material that has a thin film coating in a state of compressive stress that can result in enhanced fracture and fatigue resistance compared to the uncoated material.
