US5870351A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Broadband microfabriated ultrasonic transducer and method of fabrication
Assignee: Leland Stanford Junior University
•
Filing: 1996-10-29
•
Granted: 1999-02-09
•
Expires: 2016-10-29
Abstract
Abstract A broadband microfabricated ultrasonic transducer which includes a plurality of resonant membranes of different sizes and/or shapes supported above a conductive substrate.
Inventors
- 👤 Igal Ladabaum
- 👤 Butrus Thomas Khuri-Yakub
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-10 00:58
CPC Classifications
B; B06; B06B; B06B1/00; B06B1/02; B06B1/0292; B06B1/06; B06B1/0688; B06B1/0696; H; H02; H02N; H02N1/00; H02N1/002; H02N1/006
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
44 words
A broadband microfabricated ultrasonic transducer comprising: a substrate; a plurality of resonant membranes of different sizes with each size selected for its resonant frequency supported spaced from the substrate by an insulating support; and means for applying voltages between said membranes and said substrate.
Claim 2
Dependent Claim
44 words
A broadband microfabricated ultrasonic transducer comprising: a substrate; a plurality of resonant membranes of different sizes with each size selected for its resonant frequency supported spaced from the substrate by an insulating support; and means for applying voltages between said membranes and said substrate.
Claim 3
Dependent Claim
20 words
A broadband microfabricated transducer as in claim 1 in which the membrane is silicon nitride having a predetermined residual stress.
Claim 4
Dependent Claim
15 words
A broadband transducer as in claim 1 in which the insulating support is silicon oxide.
Claim 5
Dependent Claim
14 words
A broadband transducer as in claim 1 in which the insulating support is parylene.
Claim 6
Dependent Claim
75 words
A transducer array comprising: a substrate; a plurality of ultrasonic transducers on said substrate, each of said transducers including a plurality of resonant membranes of different sizes with each size selected to resonate at a selected frequency or frequencies, said membranes each supported spaced from said substrate by an insulating support; and means for applying voltages between selected membranes and said substrate whereby to focus and/or scan the ultrasonic energy from said plurality of membranes.
Claim 7
Dependent Claim
75 words
A transducer array comprising: a substrate; a plurality of ultrasonic transducers on said substrate, each of said transducers including a plurality of resonant membranes of different sizes with each size selected to resonate at a selected frequency or frequencies, said membranes each supported spaced from said substrate by an insulating support; and means for applying voltages between selected membranes and said substrate whereby to focus and/or scan the ultrasonic energy from said plurality of membranes.
Claim 8
Dependent Claim
20 words
A broadband microfabricated transducer as in claim 5 in which the membrane is silicon nitride having a predetermined residual stress.
Claim 9
Dependent Claim
15 words
A broadband transducer as in claim 5 in which the insulating support is silicon oxide.
Claim 10
Dependent Claim
14 words
A broadband transducer as in claim 5 in which the insulating support is parylene.
Claim 11
Dependent Claim
19 words
A broadband transducer as in claims 6, 7, or 8 in which the transducers are in a linear array.
Claim 12
Dependent Claim
20 words
A broadband transducer as in claims 6, 7, or 8 in which the transducers are in a two dimensional array.
Claim 13
Dependent Claim
66 words
A broadband microfabricated ultrasonic transducer comprising: a conductive semiconductor substrate; a plurality of silicon nitride membranes of different sizes with each size selected for its resonant frequency, said membranes supported spaced from said substrate at their edges by an insulating support; and a conductive film formed on the surface of said membranes whereby a voltage can be applied between said membranes and said conductive semiconductor substrate.
Claim 14
Dependent Claim
66 words
A broadband microfabricated ultrasonic transducer comprising: a conductive semiconductor substrate; a plurality of silicon nitride membranes of different sizes with each size selected for its resonant frequency, said membranes supported spaced from said substrate at their edges by an insulating support; and a conductive film formed on the surface of said membranes whereby a voltage can be applied between said membranes and said conductive semiconductor substrate.
Claim 15
Dependent Claim
15 words
A broadband transducer as in claim 11 in which the insulating support is silicon oxide.
Claim 16
Dependent Claim
14 words
A broadband transducer as in claim 11 in which the insulating support is parylene.
Claim 17
Dependent Claim
42 words
A broadband transducer as in claim 11 in which the membranes have areas which range from 300 to 30,000 μm 2 and thicknesses which range from 0.1 to 1 μm, and an insulator support thickness which ranges from 0.1 to 2 μm.
Claim 18
Dependent Claim
18 words
A broadband transducer as in claims 11, 12, 13, or 14 in which the membranes have different shapes.
Claim 19
Independent Claim
102 words
The method of forming a broadband ultrasonic transducer which comprises the steps of: selecting a semiconductor conductive substrate forming a thin sacrificial insulating layer on one surface of said substrate; forming a thin silicon nitride layer on the surface of said insulating layer; forming a number of etchant access holes in said silicon nitride layer, said holes being closely spaced and arranged in patterns each including a plurality of spaced access holes; etching the sacrificial insulating layer through said access holes for a period of time which etches away the sacrificial material layer to form a membrane at each pattern of holes.
Claim 20
Independent Claim
102 words
The method of forming a broadband ultrasonic transducer which comprises the steps of: selecting a semiconductor conductive substrate forming a thin sacrificial insulating layer on one surface of said substrate; forming a thin silicon nitride layer on the surface of said insulating layer; forming a number of etchant access holes in said silicon nitride layer, said holes being closely spaced and arranged in patterns each including a plurality of spaced access holes; etching the sacrificial insulating layer through said access holes for a period of time which etches away the sacrificial material layer to form a membrane at each pattern of holes.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2002-02-08 | 2002-08-10 | 2003-02-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2006-02-08 | 2006-08-10 | 2007-02-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2010-02-08 | 2010-08-10 | 2011-02-09 | $7700.00 | Window Closed / Lapsed |