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 correlate to film properties. An in situ stress measurement method is described in this paper. This optical technique, based on the cantilever one, allows to follow up the evolution of intrinsic stress with film thickness. It provides complementary information which can be correlate 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.