Bonded body and acoustic wave element

Patent metadata

Field	Value
Publication number	US-12166465-B2
Application number	US-202217579678-A
Country	US
Kind code	B2
Filing date	Jan 20, 2022
Priority date	Jul 22, 2019
Publication date	Dec 10, 2024
Grant date	Dec 10, 2024

Abstract

A bonded body includes a supporting substrate, piezoelectric material substrate and a multilayer film between the supporting substrate and piezoelectric material substrate. The multilayer film includes a lamination structure having a first layer, second layer, third layer and fourth layer in that order. The first layer and third layer are composed of silicon oxides, and the second layer and fourth layer are composed of metal oxides. The refractive index of the second layer is higher than the refractive index of the first layer and refractive index of the third layer. The refractive index of the second layer is different from the refractive index of the fourth layer.

First claim

The invention claimed is:

1. A bonded body comprising:
a supporting substrate;
a piezoelectric material substrate; and
a multilayer film between said supporting substrate and said piezoelectric material substrate,
wherein said multilayer film comprises a lamination structure comprising a first layer, a second layer in contact with the first layer, a third layer in contact with the second layer, and a fourth layer in contact with the third layer;
wherein said first layer and said third layer comprise silicon oxides, respectively;
wherein said second layer and said fourth layer comprise metal oxides, respectively;
wherein a refractive index of said second layer is higher than a refractive index of said first layer and a refractive index of said third layer; and
wherein said refractive index of said second layer is different from a refractive index of said fourth layer.

2. The bonded body of claim 1 , wherein said multilayer film comprises a plurality of said lamination structures.

3. The bonded body of claim 1 , wherein said metal oxides comprise hafnium oxide, tantalum oxide or zirconium oxide.

4. The bonded body of claim 1 , wherein a difference of said refractive index of said second layer and said refractive index of said first layer is 0.3 to 0.8.

5. The bonded body of claim 1 , wherein a difference of said refractive index of said second layer and said refractive index of said fourth layer is 0.02 or larger.

6. The bonded body of claim 1 , wherein each of a thickness of said first layer, a thickness of said second layer, a thickness of said third layer and a thickness of said fourth layer is 20 nm or larger and 300 nm or smaller.

7. The bonded body of claim 1 , further comprising a bonding layer having a composition of Si (1-v) O v (0.008≤v≤0.408) between said piezoelectric material substrate and said supporting substrate.

8. An acoustic wave device comprising:
the bonded body of claim 1 ; and
an electrode provided on said piezoelectric material substrate.

9. The acoustic wave device of claim 8 used for an acoustic wave of a frequency of 3.5 to 6 GHZ.

10. A bonded body comprising:
a supporting substrate;
a piezoelectric material substrate; and
a multilayer film between said supporting substrate and said piezoelectric material substrate,
wherein said multilayer film comprises a plurality of lamination structures, each lamination structure comprising a first layer, a second layer, a third layer and a fourth layer in the order;
wherein said first layer and said third layer comprise silicon oxides, respectively;
wherein said second layer and said fourth layer comprise metal oxides, respectively;
wherein a refractive index of said second layer is higher than a refractive index of said first layer and a refractive index of said third layer; and
wherein said refractive index of said second layer is different from a refractive index of said fourth layer.

11. A bonded body comprising:
a supporting substrate;
a piezoelectric material substrate; and
a multilayer film between said supporting substrate and said piezoelectric material substrate,
wherein said multilayer film comprises a lamination structure comprising a first layer, a second layer, a third layer and a fourth layer in the order;
wherein said first layer and said third layer comprise silicon oxides, respectively;
wherein said second layer and said fourth layer comprise metal oxides, respectively;
wherein a refractive index of said second layer is higher than a refractive index of said first layer and a refractive index of said third layer;
wherein said refractive index of said second layer is different from a refractive index of said fourth layer; and
wherein each of a thickness of said first layer, a thickness of said second layer, a thickness of said third layer and a thickness of said fourth layer is 20 nm or larger and 300 nm or smaller.

Assignees

• Ngk Insulators Ltd

Inventors

• Hattori Ryosuke
• Asai Keiichiro
• Tai Tomoyoshi
• UNO Yudai

Classifications

• H10N30/072

  by laminating or bonding of piezoelectric or electrostrictive bodies · CPC title

• H03H3/10

  for obtaining desired frequency or temperature coefficient · CPC title

• H10N30/853

  Ceramic compositions · CPC title

• H03H9/02574 Primary

  of combined substrates, multilayered substrates, piezoelectrical layers on not-piezoelectrical substrate · CPC title

• H03H3/08

  for the manufacture of resonators or networks using surface acoustic waves · CPC title