Evaluation of a fully electrical test and calibration method for MEMS capacitive accelerometers

This paper presents an evaluation of a fully electrical test and calibration method for MEMS capacitive accelerometers. The method is based on analytical expressions of the sensitivity that involve both physical parameters of the structure and electrical test parameters. To evaluate the method, an accelerometer has been designed under the Coventor environment and a nodal model parameterized with the material properties and the dimensions of the structure has been built. This model permits to perform low-level fault injection by varying the material properties and the geometrical parameters. Both global and intra-die mismatch variations can be considered. Results show that the proposed method shows the potential for testing sensitivity variations due to process scattering and permits to reduce the sensitivity dispersion after calibration. However, the improvement factor strongly depends on the characteristics of the population.