Piezoelectric laminate, production method for piezoelectric laminate, and piezoelectric element

Patent metadata

Field	Value
Publication number	US-2023142065-A1
Application number	US-202117917055-A
Country	US
Kind code	A1
Filing date	Feb 24, 2021
Priority date	Apr 6, 2020
Publication date	May 11, 2023
Grant date	—

Abstract

There is provided a piezoelectric stack, including: a substrate; an output-side bottom electrode film on the substrate; an output-side piezoelectric film, being an oxide film, on the output-side bottom electrode film; an output-side top electrode film on the output-side piezoelectric film; an input-side bottom electrode film on the substrate; an input-side piezoelectric film, being a nitride film, on the input-side bottom electrode film; an input-side top electrode film on the input-side piezoelectric film; and an ultrasonic output part and ultrasonic input part placed in such a manner as not overlapping each other when viewed from a top surface of the substrate, the ultrasonic output part comprising a stacked part of the output-side bottom electrode film, the output-side piezoelectric film, and the output-side top electrode film, the ultrasonic input part comprising a stacked part of the input-side bottom electrode film, the input-side piezoelectric film, and the input-side top electrode film.

First claim

1 . A piezoelectric stack comprising:
a substrate; an output-side bottom electrode film on the substrate; an output-side piezoelectric film, being an oxide film, on the output-side bottom electrode film; an output-side top electrode film on the output-side piezoelectric film; an input-side bottom electrode film on the substrate; an input-side piezoelectric film, being a nitride film, on the input-side bottom electrode film; an input-side top electrode film on the input-side piezoelectric film; and an ultrasonic output part and ultrasonic input part placed in such a manner as not overlapping each other when viewed from a top surface of the substrate, the ultrasonic output part comprising a stacked part of the output-side bottom electrode film, the output-side piezoelectric film, and the output-side top electrode film, the ultrasonic input part comprising a stacked part of the input-side bottom electrode film, the input-side piezoelectric film, and the input-side top electrode film.

2 . The piezoelectric stack according to claim 1 , wherein the ultrasonic output part and the ultrasonic input part are not in contact with each other.

3 . The piezoelectric stack according to claim 1 , wherein the output-side piezoelectric film, being a deposited film, contains any one of potassium sodium niobium oxide, lead-zirconium-titanium oxide, bismuth sodium titanium oxide, or bismuth ferrite.

4 . The piezoelectric stack according to claim 1 , wherein the input-side piezoelectric film, being a deposited film, contains aluminum nitride.

5 . A method of manufacturing a piezoelectric stack, comprising:
depositing an output-side bottom electrode film and an input-side bottom electrode film on a substrate; depositing an output-side piezoelectric film, being an oxide film, on the output-side bottom electrode film,; depositing a protective film that protects the output-side piezoelectric film; depositing an input-side piezoelectric film, being a nitride film, on the input-side bottom electrode film; exposing the output-side piezoelectric film by removing the protective film by etching; and depositing an output-side top electrode film on the output-side piezoelectric film and depositing an input-side top electrode film on the input-side piezoelectric film, thereby producing a stack in which an ultrasonic output part and an ultrasonic input part are placed in such a manner as not overlapping each other when viewed from a top surface of the substrate, the ultrasonic output part comprising a stacked part of the output-side bottom electrode film, the output-side piezoelectric film, and the output-side top electrode film, the ultrasonic input part comprising a stacked part of the input-side bottom electrode film, the input-side piezoelectric film, and the input-side top electrode film.

6 . The method of manufacturing a piezoelectric stack according to claim 5 , wherein the protective film is any one of a film containing silicon dioxide, a film containing lanthanum nickel oxide, or a film containing strontium ruthenium oxide.

7 . A piezoelectric element comprising:
the piezoelectric stack according to claim 1 ; a voltage applicator connected between the output-side bottom electrode film and the output-side top electrode film; and a voltage detector connected between the input-side bottom electrode film and the input-side top electrode film, wherein the output-side piezoelectric film deforms under a voltage application from the voltage applicator applying a predetermined electric field between the output-side bottom electrode film and the output-side top electrode film, and ultrasonic waves generated due to a deformation of the output-side piezoelectric film are transmitted from the ultrasonic output part, and the ultrasonic input part receives the ultrasonic waves reflected by a test object, and a voltage generated between the input-side bottom electrode film and the input-side top electrode film due to a deformation of the input-side piezoelectric film is detected by the voltage detector.

8 . The piezoelectric stack according to claim 2 , wherein the output-side piezoelectric film, being a deposited film, contains any one of potassium sodium niobium oxide, lead-zirconium-titanium oxide, bismuth sodium titanium oxide, or bismuth ferrite.

9 . The piezoelectric stack according to claim 2 , wherein the input-side piezoelectric film, being a deposited film, contains aluminum nitride.

10 . The piezoelectric stack according to claim 3 , wherein the input-side piezoelectric film, being a deposited film, contains aluminum nitride.

11 . A piezoelectric element comprising:
the piezoelectric stack according to claim 2 ; a voltage applicator connected between the output-side bottom electrode film and the output-side top electrode film; and a voltage detector connected between the input-side bottom electrode film and the input-side top electrode film, wherein the output-side piezoelectric film deforms under a voltage application from the voltage applicator applying a predetermined electric field between the output-side bottom electrode film and the output-side top electrode film, and ultrasonic waves generated due to a deformation of the output-side piezoelectric film are transmitted from the ultrasonic output part, and the ultrasonic input part receives the ultrasonic waves reflected by a test object, and a voltage generated between the input-side bottom electrode film and the input-side top electrode film due to a deformation of the input-side piezoelectric film is detected by the voltage detector.

12 . A piezoelectric element comprising:
the piezoelectric stack according to claim 3 ; a voltage applicator connected between the output-side bottom electrode film and the output-side top electrode film; and a voltage detector connected between the input-side bottom electrode film and the input-side top electrode film, wherein the output-side piezoelectric film deforms under a voltage application from the voltage applicator applying a predetermined electric field between the output-side bottom electrode film and the output-side top electrode film, and ultrasonic waves generated due to a deformation of the output-side piezoelectric film are transmitted from the ultrasonic output part, and the ultrasonic input part receives the ultrasonic waves reflected by a test object, and a voltage generated between the input-side bottom electrode film and the input-side top electrode film due to a deformation of the input-side piezoelectric film is detected by the voltage detector.

13 . A piezoelectric element comprising:
the piezoelectric stack according to claim 4 ; a voltage applicator connected between the output-side bottom electrode film and the output-side top electrode film; and a voltage detector connected between the input-side bottom electrode film and the input-side top electrode film, wherein the output-side piezoelectric film deforms under a voltage application from the voltage applicator applying a predetermined electric field between the output-side bottom electrode film and the output-side top electrode film, and ultrasonic waves generated due to a deformation of the output-side piezoelectric film are transmitted from the ultrasonic output part, and the ultrasonic input part receives the ultrasonic waves reflected by a test object, and a voltage generated between the input-side bottom electrode film and the input-side top electrode film due to a deformation of the input-side piezoelectric film is detected by the voltage detector.

Assignees

• Sumitomo Chemical Co

Inventors

• Kuroda Toshiaki
• Shibata Kenji
• Watanabe Kazutoshi
• Kimura Takeshi

Classifications

• H10N39/00 Primary

  Integrated devices, or assemblies of multiple devices, comprising at least one piezoelectric, electrostrictive or magnetostrictive element covered by groups H10N30/00 – H10N35/00 · CPC title

• H10N30/8542

  Alkali metal based oxides, e.g. lithium, sodium or potassium niobates · CPC title

• H10N30/88

  Mounts; Supports; Enclosures; Casings · CPC title

• G01H11/08

  using piezoelectric devices · CPC title

• H10N30/853

  Ceramic compositions · CPC title