Residual Stresses Measuring of Electrostatic MEM switches by Piezoelectric Layers

Due to the unique structure and small scale of Micro-Electro-Mechanical Systems (MEMS), residual stresses during the deposition processes can have a profound affect on the functionality of the MEMS structures. Typically, material properties of thin films used in surface micromachining are not controlled during deposition. The residual stress, for example, tends to vary significantly for different deposition methods. Currently, few techniques are available to measure the residual stress in MEMS devices. In this paper, we introduce a new method to estimate the residual stress by calculating the applied voltage to the piezoelectric layers