Stacked substrate having piezoelectric film, method for manufacturing stacked substrate, and piezoelectric element

Patent metadata

Field	Value
Publication number	US-2025221314-A1
Application number	US-202418999251-A
Country	US
Kind code	A1
Filing date	Dec 23, 2024
Priority date	Dec 27, 2023
Publication date	Jul 3, 2025
Grant date	—

Abstract

There is provided a stacked substrate including: a substrate; and a piezoelectric film provided on the substrate and composed of an alkali niobium oxide containing potassium, sodium, niobium, and oxygen, wherein SIMS analysis of a region of the substrate ranging from a surface of the substrate on which the piezoelectric film is provided to a depth of 1 μm toward a surface of the substrate opposite to the surface on which the piezoelectric film is provided, reveals that a concentration of potassium is 5E15 cm −3 or less, and a concentration of sodium is 5E15 cm −3 or less, and an orientation rate of crystals constituting the piezoelectric film in a (001) direction is 96% or more.

First claim

1 . A stacked substrate comprising:
a substrate; and a piezoelectric film provided on the substrate and composed of an alkali niobium oxide containing potassium, sodium, niobium, and oxygen, wherein SIMS analysis of a region of the substrate ranging from a surface of the substrate on which the piezoelectric film is provided to a depth of 1 μm toward a surface of the substrate opposite to the surface on which the piezoelectric film is provided, reveals that a concentration of potassium is 5E15 cm −3 or less, and a concentration of sodium is 5E15 cm −3 or less, and an orientation rate of crystals constituting the piezoelectric film in a (001) direction is 96% or more.

2 . The stacked substrate according to claim 1 , wherein the piezoelectric film has a piezoelectric constant e 31 of 7 C/m 2 or more.

3 . The stacked substrate according to claim 1 , wherein the substrate is any one of a semiconductor substrate, a resin substrate, a glass substrate, and a metal substrate.

4 . The stacked substrate according to claim 1 , wherein the substrate is a silicon substrate, and has a semiconductor element on the substrate.

5 . The stacked substrate according to claim 4 , wherein the substrate has a protective film that protects the semiconductor element.

6 . A method for manufacturing a stacked substrate, the method comprising:
preparing a substrate; and depositing a piezoelectric film composed of an alkali niobium oxide containing potassium, sodium, niobium, and oxygen on the substrate by a sputtering method, wherein in the depositing the piezoelectric film, a depositing temperature is 400° C. or more and less than 500° C., an oxygen partial pressure is 0.0025 Pa or more and less than 0.01 Pa, and an atmospheric pressure is 0.03 Pa or more and less than 0.1 Pa.

7 . A piezoelectric element comprising:
a substrate; and a piezoelectric film provided on the substrate and composed of an alkali niobium oxide containing potassium, sodium, niobium, and oxygen, wherein SIMS analysis of a region of the substrate ranging from a surface of the substrate on which the piezoelectric film is provided to a depth of 1 μm toward a surface of the substrate opposite to the surface on which the piezoelectric film is provided, reveals that a concentration of potassium is 5E15 cm −3 or less, and a concentration of sodium is 5E15 cm −3 or less, and an orientation rate of crystals constituting the piezoelectric film in a (001) direction is 96% or more.

Assignees

• Sumitomo Chemical Co

Inventors

• Tanaka Yasunori
• Shibata Kenji
• Kuroda Toshiaki
• Watanabe Kazutoshi

Classifications

• H10N30/2047

  Membrane type · CPC title

• H10N30/076 Primary

  by vapour phase deposition · CPC title

• H10N39/00

  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 Primary

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

• C23C14/088

  of the type ABO3 with A representing alkali, alkaline earth metal or Pb and B representing a refractory or rare earth metal · CPC title