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US 5,894,452 AGranted
Microfabricated ultrasonic immersion transducer
AssigneeThe Board of Trustees of the Leland Stanford Junior University
InventorsIgal Ladabaum, Butrus Thomas Khuri-Yakub, Hyongsok Soh
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Abstract
An ultrasonic capacitance transducer having a sealed membrane supported above a conductive substrate by thin insulating material to form a sealed evacuated cavity whereby the transducer can operate immersed in fluid.
Claims18
A microfabricated ultrasonic transducer including:
- a conductive substrate;
- a plurality of silicon nitride membranes having one or more holes;
- an insulating support supporting, each of said membranes above said substrate;
- and
- a silicon nitride layer formed by chemical vapor deposition on said membranes extending partially into and sealing said openings to form a sealed cavity defined by said substrate, insulating support and sealed membrane;
- and
- a conductive film on the outer surface of the silicon nitride membrane.
4 more elements
An ultrasonic transducer including:
- a conductive silicon substrate;
- a plurality of silicon nitride membranes having one or more apertures less than 0.3 microns in diameter;
- supports comprising thin insulating material supporting each of said membranes above the substrate;
- a sealing silicon nitride layer formed on said membranes extending at least partially into said apertures to seal the membrane;
- a thin metal film making electrical connection to the outer surface of said silicon nitride layer;
- and,
- a thin metal film making electrical connection to the other surface of said conductive substrate.
4 more elements
Dependencies are inferred from the claim text.