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US 11,235,352 B2Granted
Capacitive micromachined ultrasonic transducer and manufacturing method thereof
AssigneeCanon Kabushiki Kaisha
InventorTakahiro Akiyama
Life of this patent
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Abstract
A high output and high reliability capacitive micromachined ultrasonic transducer (CMUT) is provided. The capacitive micromachined ultrasonic transducer has a concave portion on a surface of at least one insulating film. The surface faces an air gap.
Claims28
A capacitive micromachined ultrasonic transducer (CMUT) comprising:
- a first electrode;
- a first insulating film on the first electrode;
- and
- a vibrating membrane across an air gap from the first insulating film,
- wherein the vibrating membrane includes a second electrode and a second insulating film at a position facing the air gap,
- wherein a concave portion is formed on either one of a surface of the first insulating film facing the air gap and a surface of the second insulating film facing the air gap, and
- wherein, when a region size of the surface facing the air gap of said one of the first insulating film and the second insulating film on which the concave portion is formed is defined as A, a size of a region where the concave portion is formed, defined as B, is smaller than a size of a region where the concave portion is not formed, defined as A-B.
4 more elements
A method for manufacturing a capacitive micromachined ultrasonic transducer (CMUT), the method comprising:
- forming a first insulating film on a first electrode;
- forming a sacrificial layer on the first insulating film;
- forming a second insulating film on the sacrificial layer;
- forming a second electrode on the second insulating film;
- forming an etching hole by removing a part of the second insulating film to expose a part of the sacrificial layer;
- and
- forming an air gap by removing the sacrificial layer,
- wherein the sacrificial layer is formed in such a manner that by removing the sacrificial layer, a concave portion is formed on a surface of the second insulating film facing the air gap, and
- wherein, when a region size of the surface facing the air gap of said one of the first insulating film and the second insulating film on which the concave portion is formed is defined as A, a size of a region where the concave portion is formed, defined as B, is smaller than a size of a region where the concave portion is not formed, defined as A-B.
6 more elements
A method for manufacturing a capacitive micromachined ultrasonic transducer (CMUT), the method comprising:
- forming a first insulating film on a first electrode;
- forming a sacrificial layer on the first insulating film;
- forming a second insulating film on the sacrificial layer;
- forming a second electrode on the second insulating film;
- forming an etching hole by removing the second insulating film to expose a part of the sacrificial layer;
- and
- forming an air gap by removing the sacrificial layer,
- wherein the sacrificial layer is formed in such a manner that by removing the sacrificial layer, when a region size of the surface facing the air gap of said one of the first insulating film and the second insulating film on which the concave portion is formed is defined as A, a size of a region where the concave portion is formed, defined as B, is smaller than a size of a region where the concave portion is not formed, defined as A-B.
5 more elements
Dependencies are inferred from the claim text.