A novel fatigue test with ramping stress amplitude to evaluate fatigue behavior of polysilicon thin films

This paper presents a new experimental method to estimate the fatigue behavior of polysilicon thin films by using cyclic loading with gradually increasing stress amplitude. This method solves fundamental problems of conventional fatigue experiments with constant amplitude. The fatigue crack extension process determining fatigue lifetime was estimated by the well-known Paris law with two unknown parameters. These were fit to the results of two methods performed on specimens with two different situations of etching damage. It is shown that the new experimental method can be used to predict the fatigue lifetime in a more efficient manner.