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US 5,619,476 AGranted
Electrostatic ultrasonic transducer
AssigneeThe Board of Trustees of the Leland Stanford Jr. Univ.
InventorsMatthew I. Haller, Butrus T. Khuri-Yakub
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Abstract
An electrostatic ultrasonic transducer formed on a semiconductor substrate by micro-machining wherein the transducer includes a silicon nitride membrane supported above the surface of the substrate by insulating supports; and the substrate and membrane define the electrodes of the transducer.
Claims13
An ultrasonic transducer which includes:
- a substrate having first and second major surfaces;
- a layer of insulator material having a plurality of void regions and support regions formed on one major surface of said substrate;
- a layer of silicon nitride having residual stress formed on and supported by said layer of insulator material and extending over said void regions spaced from said one major surface of said substrate to form a membrane capable of vibrating at each of said void regions, said silicon nitride layer including openings communicating with each of said void regions;
- a thin conductive film formed on an outer surface of said silicon nitride layer and a thin conductive film formed on a major surface of said substrate whereby to form a plurality of transducers one at each of said void regions.
1 more element
Dependencies are inferred from the claim text.