Accelerometer with Low Sensitivity to Thermo-Mechanical Stress

A method of compensating thermo-mechanical stress accumulated in a microelectromechanical structure, comprising the steps of:

• coupling a stationary electrode to a moveable electrode that is attached to a proof mass, the stationary electrode forming a sensing capacitor with the moveable electrode such that movement of the proof mass leads to a capacitive variation of the sensing capacitor that is further converted to a sensing output;
• determining a level of the thermo-mechanical stress that is accumulated in the structure and impacts the sensing capacitor;
• determining an offset value and a sensitivity drift associated with the sensing output according to the level of the thermo-mechanical stress;
• incorporating at least one elastic element on a coupling structure that couples the stationary electrode to at least one anchor on a substrate;
• and
• adjusting location, geometry and configuration of the at least one elastic element so as to compensate the offset value and the sensitivity drift.

A microelectromechanical structure that compensates thermo-mechanical stress, comprising:

• a proof mass that is suspended above a substrate and attached with at least one moveable electrode;
• a plurality of stationary electrodes, electrically coupled to the at least one moveable electrode, the plurality of stationary electrodes forming at least one sensing capacitor with the at least one moveable electrode such that movement of the proof mass leads to a capacitive variation of the at least one sensing capacitor;
• and
• wherein a plurality of coupling structures are used to couple the plurality of stationary electrodes among each other and to at least one anchor on the substrate, a plurality of elastic elements being incorporated on at least one of the plurality of coupling structures, location, geometry and configuration of each elastic element and the total number of elastic elements in the plurality of elastic elements being adjusted to compensate impact of the thermo-mechanical stress on the at least one sensing capacitor.