A direct method of determining complex depth profiles of residual stresses in thin films on a nanoscale

A cantilever method of determining complex depth profiles of residual stresses is presented by means of a 840 nm thin Ni film on a Si substrate. The technique developed is based on the fabrication of a micro-cantilever and the subsequent gradual reduction of film thickness using a focused ion beam workstation. The deflection as a function of film thickness is measured directly from SEM images, and the stress distribution in the thin film is determined by means of a straightforward calculation procedure. The method can be applied to crystalline as well as amorphous materials and permits stress profiles on a nanoscale to be determined.