Real Time Optical Method of Stress Measurements in Thin Films

Techniques generally used to measure stress in thin films cannot give sufficient information to be correlated with the film properties. An in-situ stress measurement method is described in this paper. This optical technique, based on the cantilever method, makes it possible to follow up the evolution of intrinsic stress with the film thickness. It provides complementary information which can be correlated with film microstructure. Moreover, after deposition, this technique determines the Young's modulus and thermal expansion coefficient of the film by measuring the thermal stress during cooling. (Author)