Capacitance-based pressure sensor including pressure vessel(s)
First Claim
1. A pressure sensor comprising:
- a semiconductor substrate that includes a first cavity;
a pressure vessel having a cross section that defines a void, the void having a shape that is configured to change based on a change of pressure difference between a cavity pressure in the first cavity and a vessel pressure in the pressure vessel, at least a first portion of the pressure vessel suspended in the first cavity; and
a capacitive structure coupled to the first portion of the pressure vessel, the capacitive structure configured to provide a first capacitance that changes with the shape of the void.
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Accused Products
Abstract
Techniques are described herein that perform capacitance-based pressure sensing using pressure vessel(s). A pressure vessel is an object that has a cross section that defines a void. The void has a shape that is configured to change based on a change of pressure difference between a cavity pressure in a cavity in which at least a portion of the pressure vessel is suspended and a vessel pressure in the pressure vessel. The pressure vessel may be formed in the shape of an enclosed loop (e.g., along a path that is perpendicular to the cross section), resulting in a looped pressure vessel. For instance, an end of the pressure vessel may be connected to another end of the pressure vessel to form the enclosed loop.
11 Citations
28 Claims
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1. A pressure sensor comprising:
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a semiconductor substrate that includes a first cavity; a pressure vessel having a cross section that defines a void, the void having a shape that is configured to change based on a change of pressure difference between a cavity pressure in the first cavity and a vessel pressure in the pressure vessel, at least a first portion of the pressure vessel suspended in the first cavity; and a capacitive structure coupled to the first portion of the pressure vessel, the capacitive structure configured to provide a first capacitance that changes with the shape of the void. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22)
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23. A method comprising:
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providing a semiconductor substrate that includes a cavity; fabricating a pressure vessel having a cross section that defines a void, the void having a shape that is configured to change based on a change of pressure difference between a cavity pressure in the cavity and a vessel pressure in the pressure vessel, at least a portion of the pressure vessel suspended in the cavity; and fabricating a capacitive structure coupled to the portion of the pressure vessel, the capacitive structure configured to provide a capacitance that changes with the shape of the void. - View Dependent Claims (24, 25)
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26. A method comprising:
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embedding at least a support portion of a pressure vessel that is in a shape of an enclosed loop in a semiconductor substrate external to a cavity in the semiconductor substrate in which the pressure vessel is suspended, the pressure vessel having a cross section that defines a void, the void having a shape that is configured to change based on a change of pressure difference between a cavity pressure in the cavity and a vessel pressure in the pressure vessel, the enclosed loop having an inner perimeter and an outer perimeter; providing first and second metallization layers on respective inner and outer perimeters of the enclosed loop, the first metallization layer being electrically connected to a portion of the semiconductor substrate that is within the inner perimeter of the enclosed loop; routing a first metallization trace from the portion of the semiconductor substrate that is within the inner perimeter of the enclosed loop to a first electrode on a top surface of the semiconductor substrate that is outside an isolation barrier that surrounds the cavity; and routing a second metallization trace from the second metallization layer to a second electrode on the top surface of the semiconductor substrate that is outside the isolation barrier.
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27. A method comprising:
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receiving a cavity pressure in a cavity that is included in a semiconductor substrate of a pressure sensor; receiving a vessel pressure in a pressure vessel of the pressure sensor, at least a portion of the pressure vessel being suspended in the cavity; and measuring a capacitance that changes with a shape of a void that is defined by a cross section of the pressure vessel using a capacitive structure that is coupled to the portion of the pressure vessel. - View Dependent Claims (28)
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Specification