A capacitance and optical method for the static and dynamic characterization of micro electro mechanical systems (MEMS) devices

As the micro technology field expands, the need of simple and standardized procedures to precisely evaluate device functionality, realibility and quality of micro electro mechanical systems devices increases. In this paper the application of two empirical methods suitable for the static and the dynamic characterization of micrometersized structures is proposed. The first methodology is based on capacitance measurements and finds simple application in case of comb-finger actuated devices. The second one is based on the Doppler phenomenon combined with laser optical interferometry allowing the characterization of a wide range of structures. The methodologies are applied to a reliability test structure specifically designed at STMicroelectronics for studying the fatigue behaviour of the structural material involved in the fabrication of their commercial products. This case of study highlights how the techniques may be coupled to usual design approaches for completing and verifying the information given by theory and simulations; thus improving the entire development cycle.