Flexible Design Techniques for Polysilicon MEMS Process

MEMS (micro electro mechanical systems) products have significant growth potential, and are being used in an increasing number of applications. One issue with MEMS devices is manufacture, as current MEMS manufacturing processes not standardized. Design techniques were developed to allow a single MEMS manufacturing flow to meet a wide range of accelerometer specifications. One technique is "Metal on proof mass", this is a design method that adds thermally dissimilar materials (such as metal) to the accelerometer proof mass, and isolates the proof mass from resulting thermal stresses. Another technique is "variable gap sense capacitance", which uses two different sensing gaps in capacitive transducers. This allows z-axis transducers to provide increased output and improved linearity.