MEASUREMENTS OF ADHERENCE OF RESIDUALLY STRESSED THIN-FILMS BY INDENTATION .2. EXPERIMENTS WITH ZNO/SI

Indentation-induced delamination between thin films of ZnO and Si substrates is examined. Delamination occurs by the growth of lateral cracks, either along the interface or within the film adjacent to the interface. The crack path is determined by the indenter load and the film thickness, as well as by residual stresses formed during deposition. A change in crack path from the interface to the film, accompanied by an increase in crack radius, is observed and is interpreted as a buckling-induced stress intensification. The interface fracture toughness is estimated from the relative crack lengths in the buckled and unbuckled films.