Microelectromechanical sensing structure for a capacitive acoustic transducer including an element limiting the oscillations of a membrane, and manufacturing method thereof
First Claim
1. A microelectromechanical sensing structure, comprising:
- a substrate of semiconductor material;
a sensing capacitor that includes;
a rigid conductive electrode;
a conductive membrane coupled to the substrate and arranged between the substrate and the electrode, the membrane having a first surface and a second surface, the membrane being configured to deform in response to pressure, the sensing capacitor having a capacitance that varies as a function of the deformation of the membrane;
a first chamber delimited at least in part by the substrate and the first surface of the membrane;
a second chamber being delimited at least in part by the electrode and the second surface of the membrane; and
a beam located in the first chamber and coupled to the substrate, the beam being configured to limit oscillations of the membrane when the pressure has an amplitude that is above a first threshold, thereby preventing plastic deformation of the membrane.
2 Assignments
0 Petitions
Accused Products
Abstract
A microelectromechanical sensing structure for a capacitive acoustic transducer, including: a semiconductor substrate; a rigid electrode; and a membrane set between the substrate and the rigid electrode, the membrane having a first surface and a second surface, which are in fluid communication, respectively, with a first chamber and a second chamber, respectively, the first chamber being delimited at least in part by a first wall portion and a second wall portion formed at least in part by the substrate, the second chamber being delimited at least in part by the rigid electrode, the membrane being moreover designed to undergo deformation following upon incidence of pressure waves and facing the rigid electrode so as to form a sensing capacitor having a capacitance that varies as a function of the deformation of the membrane. The structure moreover includes a beam, which is connected to the first and second wall portions and is designed to limit the oscillations of the membrane.
21 Citations
21 Claims
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1. A microelectromechanical sensing structure, comprising:
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a substrate of semiconductor material; a sensing capacitor that includes; a rigid conductive electrode; a conductive membrane coupled to the substrate and arranged between the substrate and the electrode, the membrane having a first surface and a second surface, the membrane being configured to deform in response to pressure, the sensing capacitor having a capacitance that varies as a function of the deformation of the membrane; a first chamber delimited at least in part by the substrate and the first surface of the membrane; a second chamber being delimited at least in part by the electrode and the second surface of the membrane; and a beam located in the first chamber and coupled to the substrate, the beam being configured to limit oscillations of the membrane when the pressure has an amplitude that is above a first threshold, thereby preventing plastic deformation of the membrane. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A microelectromechanical acoustic transducer comprising:
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a sensitive structure that includes; a semiconductor substrate having a through opening delimited by sidewalls; a sensing capacitor that includes; a rigid conductive electrode; a conductive membrane coupled to the substrate and located between the substrate and the electrode, the membrane having a first surface and a second surface, the membrane being configured to deform in response to pressure, the sensing capacitor having a capacitance that varies as a function of the deformation of the membrane; a first chamber delimited at least in part by the sidewalls of the through opening of the substrate and the first surface of the membrane; a second chamber being delimited at least in part by the electrode and the second surface of the membrane; and a beam located in the first chamber and coupled to the substrate, the beam being configured to limit oscillations of the membrane when the pressure has an amplitude that is above a first threshold, the first threshold being within an elastic deformation range of the membrane; and an electronic read circuit operatively coupled to said sensitive structure and configured for output an electrical detection signal indicative of the capacitance of said sensing capacitor. - View Dependent Claims (11, 12, 13, 14, 15)
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16. An electronic device comprising:
an acoustic transducer including; a sensitive structure that includes; a semiconductor substrate having a through opening delimited by sidewalls; a sensing capacitor that includes; a rigid conductive electrode; a conductive membrane coupled to the substrate and located between the substrate and the electrode, the membrane having a first surface and a second surface, the membrane being configured to deform in response to pressure, the sensing capacitor having a capacitance that varies as a function of the deformation of the membrane; a first chamber delimited at least in part by the sidewalls of the through opening of the substrate and the first surface of the membrane; a second chamber being delimited at least in part by the electrode and the second surface of the membrane; and a beam located in the first chamber and coupled to the substrate, the beam being configured to limit oscillations of the membrane when the pressure has an amplitude that is above a first threshold, wherein below the first threshold the membrane is configured to elastically deform and above the first threshold the membrane is configured to plastically deform; and an electronic read circuit operatively coupled to said sensitive structure and configured for output an electrical detection signal indicative of the capacitance of said sensing capacitor. - View Dependent Claims (17)
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18. A process comprising:
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forming a rigid electrode; and forming a conductive membrane that is coupled to a substrate and arranged between the substrate and the electrode, the membrane having a first surface and a second surface, the membrane being configured to deform in response to pressure, the membrane and the electrode forming a sensing capacitor having a capacitance that varies as a function of the deformation of the membrane; forming a first chamber that is delimited at least in part by the electrode and the second surface of the membrane; forming a second chamber that is delimited at least in part by the first surface of the membrane and the substrate; and forming a beam that is coupled to the substrate and is configured to limit oscillations of the membrane that are above a threshold, thereby preventing plastic deformation of the membrane. - View Dependent Claims (19, 20, 21)
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Specification