# US 9,752,924 B2 · Capacitance type transducer and method of manufacturing the same

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- Number: US 9,752,924 B2
- Document ID: US9752924B2
- Status: Granted
- Kind: B2
- Application number: 14/511,365
- Filed: 2014-10-10
- Published: 2015-04-23
- Granted: 2017-09-05
- Earliest claimed: 2013-10-22
- Assignees: Canon Kabushiki Kaisha
- Applicants: Canon Kabushiki Kaisha
- Inventors: Takahiro Akiyama; Kazutoshi Torashima
- Web page: https://patentgrep.com/patent/US9752924B2

## CPC

- G01H 9/008: {by using ultrasonic waves (measuring position using ultrasonic waves G01S15/02)}
- B06B 1/0292: {Electrostatic transducers, e.g. electret-type}
- G01H 11/06: by electric means
- G01H: MEASUREMENT OF MECHANICAL VIBRATIONS OR ULTRASONIC, SONIC OR INFRASONIC WAVES
- B06B: METHODS OR APPARATUS FOR GENERATING OR TRANSMITTING MECHANICAL VIBRATIONS OF INFRASONIC, SONIC, OR ULTRASONIC FREQUENCY, {e.g.} FOR PERFORMING MECHANICAL WORK IN GENERAL (for particular applications, see the relevant subclasses, e.g. B07B1/40, B23Q17/12, B24B31/06; measurement of mechanical vibrations G01H; in direction finding, locating, distance or velocity measuring G01S; {generating seismic energy G01V1/02}; control of mechanical vibrations in general G05D; sound-producing devices, e.g. bells, sirens, whistles G10K, {e.g. methods or devices for transmitting, conducting, or directing sound in general G10K11/00}; generation of electrical oscillations H03B; electromechanical resonators in general H03H; electromechanical transducers {for communication techniques, e.g. microphones, speakers} H04R)

## Abstract

A capacitance type transducer includes a plurality of cells each having a structure in which a vibrating film is supposed so as to be vibrated. The vibrating film includes: a second electrode formed so that a gap is interposed between the second electrode and a first electrode; and an insulating film formed on the second electrode. The capacitance transducer manufacturing method includes: forming a sacrificial layer on the first electrode; forming a layer including a vibrating film on the sacrificial layer; forming an etching hole to remove the sacrificial layer; and forming a sealing film for sealing the etching hole. Before forming the etching hole to remove the sacrificial layer, a through hole is formed in an insulating film on the second electrode, and a conductor film is formed on the insulating film having the through hole to electrically connect a conductor in the through hole and the second electrode.

## Claims

### Claim 1

A method of manufacturing a capacitance type transducer comprising a plurality of cells each having a structure in which a vibrating film is supported so as to be vibrated, the vibrating film comprising: a second electrode formed so that a gap is interposed between the second electrode and a first electrode; and an insulating film formed on the second electrode,
the method comprising:
forming a sacrificial layer on the first electrode;
forming a layer including the vibrating film on the sacrificial layer;
forming an etching hole to remove the sacrificial layer; and
forming a sealing film configured to seal the etching hole,
the method further comprising, before the forming an etching hole to remove the sacrificial layer:
forming a through hole in the insulating film on the second electrode; and
forming a conductor film on the insulating film including the through hole to electrically connect a conductor in the through hole and the second electrode to each other,
wherein the conductor film electrically connects second electrodes of the plurality of cells to each other.

### Claim 2 (depends on 1)

The method according to claim 1, further comprising:
removing, with use of the conductor film as an etch stop film, at least a part of a portion overlapping the gap in an orthographic projection of the sealing film onto the first electrode side up to a surface of the etch stop film after forming the sealing film; and
patterning the etch stop film to form wiring configured to electrically connect the second electrodes in at least a part of the plurality of cells.

### Claim 3 (depends on 1)

The method according to claim 1, further comprising patterning the conductor film to form wiring configured to electrically connect the second electrodes in at least a part of the plurality of cells before the forming a sealing film configured to seal the etching hole.

### Claim 4 (depends on 1)

The method according to claim 1, wherein the sealing film and the insulating film on the second electrode are formed of the same material.

### Claim 5 (depends on 4)

The method according to claim 4, wherein the same material comprises silicon nitride.

### Claim 6 (depends on 1)

The method according to claim 1, wherein the conductor film comprises one of a titanium film, a stacked film including a titanium layer, an aluminum film, a stacked film including an aluminum layer, and an alloy film containing at least one of titanium or aluminum.