Stress sensing devices and methods
AssigneeInfineon Technologies AG
InventorsUdo Ausserlechner, Mario Motz
Life of this patent
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Abstract
Embodiments relate to stress sensors and methods of sensing stress. In an embodiment, a stress sensor comprises a vertical resistor. The vertical resistor can comprise, for example, an n-type resistor and can have various operating modes. The various operating modes can depend on a coupling configuration of terminals of the resistor and can provide varying piezo-coefficients with very similar temperature coefficients of resistances. Comparisons of resistances and piezo-coefficients in differing operating modes can provide a measure of mechanical stresses acting on the device.
Claims21
A stress sensing device comprising:
- a semiconductor substrate;
- a layer arranged within the semiconductor substrate,
- a plurality of contacts arranged on a first side of the layer, wherein
- a first resistive element formed within the layer between a first pair of contacts of the plurality of contacts;
- a second resistive element formed within the layer between a second pair of contacts of the plurality of contacts;
- wherein the first resistive element and the second resistive element show a substantially identical response to temperature changes, and a ratio of the first and second resistive elements varies with applied mechanical stress.
A sensor device comprising:
- a layer;
- and
- at least three contacts spaced apart from one another in the layer, the at least three contacts being coupleable in a first configuration for a first operating mode of the sensor device in which a current in the layer has a first ratio of horizontal to vertical components with respect to a die surface, and
- in a second configuration different from the first for a second operating mode of the sensor device in which a current in the layer has a second ratio of horizontal to vertical components, wherein a ratio of a resistance between at least two of the contacts in the first operating mode and a resistance between at least two of the contacts in the second operating mode is related to mechanical stress in the sensor device.
Dependencies are inferred from the claim text.