Micromechanical pressure-sensor element and method for its production
AssigneeRobert Bosch GmbH
InventorsMarcus Ahles, Hubert Benzel
Life of this patent
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Abstract
A very robust sensor element for an absolute-pressure measurement is described, which is suitable for high temperatures and able to be miniaturized to a large extent. The micromechanical pressure-sensor element includes a sensor diaphragm having a rear-side pressure connection and at least one dielectrically insulated piezo resistor for signal acquisition. Furthermore, the pressure-sensor element has a front-side reference volume, which is sealed by a cap structure spanning the sensor diaphragm. The cap structure is realized as thin-film structure.
Claims11
A micromechanical pressure-sensor element, comprising:
- a sensor diaphragm;
- a rear-side pressure connection to the sensor diaphragm;
- at least one dielectrically insulated piezo resistor for signal acquisition;
- and
- a front-side reference volume, which is sealed by a cap structure spanning the sensor diaphragm, wherein the cap structure is a thin-film structure.
A method for producing a micromechanical pressure-sensor element, the method comprising:
- providing a sensor diaphragm having a rear-side pressure connection to the sensor diaphragm;
- providing at least one dielectrically insulated piezo resistor for signal acquisition;
- following the realization of the at least one dielectrically insulated piezo resistor, producing a cap structure in a region of the sensor diaphragm above the sensor diaphragm using thin-film technology;
- and
- exposing the sensor diaphragm relative to the cap structure by performing sacrificial layer etching, during which a front-side reference volume is produced.
Dependencies are inferred from the claim text.