Finding the critical impact energy for micro debris generation in MEMS inertial sensors

The work presents a consistent follow-up on a study to identify the critical impact energy of suspended polysilicon masses onto stoppers [1], to prevent creation of debris and particles which affect the lifetime stability of MEMS inertial sensors. The proposed test device is capable of detecting debris generation by monitoring the leakage current between buried electrodes underneath the mass-stopper contact region. Results indicate that leakage begins to appear at 15 nJ impact energy, and manifests on 100% of tested structures at energies of 25 nJ. Optical analyses after device uncapping confirm the prediction, validating the test method.