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

Abstract

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.