On-chip tests for the characterization of the mechanical strength of polysilicon

Microelectromechanical systems (MEMS) are nowadays widespread in the sensor market with a number of different applications. New production techniques and ever smaller device geometries require a continuous investigation of potential failure mechanisms in such devices. This work presents an experimental on-chip setup to assess the geometry- and material-dependent strength of stoppers adopted to limit the deformation of movable parts, using an electrostatically actuated device. A series of comb-fingers and parallel plates are used to provide a rather large stoke to a shuttle, connected to the anchors through flexible springs. Upon application of a varying voltage, failure of stoppers of variable size is observed and confirmed by postmortem ΔC-V curves. Results of an experimental campaign are collected to infer the stochastic property of the strength of polycrystalline, columnar silicon films.