Measurement of residual stress in thin films using the optical microprobe

The laser optical microprobe is a powerful tool for studying the spatial variation of residual stress exploiting the sensitivity of Raman and luminescence spectra to the local stress. Here, using two different examples, we consider some issues determining the depth and lateral resolution of these techniques and their use in stress mapping in thin films. The first example involves Raman microprobe studies of a strained GeSi alloy quantum wire structure. The second example involves stress mapping using chromium ion luminescence in alumina films grown by high temperature thermal oxidation of NiAl single crystals.