Dominant factor on fracture strength of thin film comprising of copper helical nano-elements grown by glancing angle deposition

The purpose of this study is to investigate the dominant factor on the fracture strength of thin film comprising of copper (Cu) helical nano-elements, which are grown by the glancing angle deposition technique. By changing the deposition angle in the GLAD, three types of thin films with different number density of Cu helical nano-elements are produced. Crack initiation experiments are carried out using cantilever specimens where the thin film is constrained by a substrate and a stainless cantilever. Near the edge of thin film, the critical forces applied to Cu helical nano-elements at the fracture are mostly consistent regardless of the number density of nano-elements although the critical average stresses are different. This result signifies that the fracture of the thin film is governed by the strength of nano-element.