# US 2022/0037582 A1 · Piezoelectric body and mems device using same

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- Number: US 2022/0037582 A1
- Document ID: US20220037582A1
- Status: Published application
- Kind: A1
- Application number: 17/276,464
- Filed: 2019-11-26
- Published: 2022-02-03
- Earliest claimed: 2018-12-11
- Assignees: National Institute of Advanced Industrial Science and Technology
- Applicants: National Institute of Advanced Industrial Science Technology
- Inventors: Masato UEHARA; Hiroshi YAMADA; Morito AKIYAMA; Sri Ayu ANGGRAINI; Kenji HIRATA
- Web page: https://patentgrep.com/patent/US20220037582A1

## CPC

- H10N 30/302: {Sensors}
- H10N 30/708: {Intermediate layers, e.g. barrier, adhesion or growth control buffer layers}
- B81B 3/0018: {Structures acting upon the moving or flexible element for transforming energy into mechanical movement or vice versa, i.e. actuators, sensors, generators}
- H10N 30/50: having a stacked or multilayer structure
- H10N 30/853: Ceramic compositions
- B81B 2201/0235: Accelerometers
- B81B 2201/0242: Gyroscopes
- B81B 2201/0257: Microphones or microspeakers
- B81B 2201/0264: Pressure sensors
- H10N 30/076: by vapour phase deposition
- H10N: ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- B81B: MICROSTRUCTURAL DEVICES OR SYSTEMS, e.g. MICROMECHANICAL DEVICES (piezoelectric, electrostrictive or magnetostrictive elements per se H10N30/00, H10N35/00)

## Abstract

There are provided a piezoelectric body of ytterbium-doped aluminum nitride, having a greater piezoelectric coefficient d33 or g33 than those not doped with ytterbium, and a MEMS device using the piezoelectric body. The piezoelectric body is represented by a chemical formula Al1-xYbxN where a value of x is more than 0 and less than 0.37 and having a lattice constant ratio c/a in a range of 1.53 or more and less than 1.6. The piezoelectric body with such a configuration has a greater piezoelectric coefficient d33 or g33 than those not doped with ytterbium.

## Claims

### Claim 1

A nitride material represented by a chemical formula Al1-xYbxN where a value of x is more than 0 and less than 0.37 and having a lattice constant ratio c/a in a range of 1.53 or more and less than 1.6.

### Claim 2 (depends on 1)

The nitride material according to claim 1, wherein the value of x is within a range of more than 0.27 and less than 0.37.

### Claim 3 (depends on 2)

The nitride material according to claim 2, wherein the lattice constant ratio c/a is within a range of 1.53 or more and 1.555 or less.

### Claim 4 (depends on 1)

The nitride material according to claim 1, wherein the value of x is within a range of more than 0 and less than 0.1.

### Claim 5 (depends on 4)

The nitride material according to claim 4, wherein the lattice constant ratio c/a is within a range of 1.57 or more and less than 1.6.

### Claim 6 (depends on 10)

A piezoelectric body wherein the piezoelectric body according to claim 10 is disposed on a substrate, and at least an intermediate layer is disposed between the piezoelectric body and the substrate.

### Claim 7 (depends on 6)

The piezoelectric body according to claim 6, wherein the intermediate layer includes at least one of aluminum nitride, gallium nitride, indium nitride, titanium nitride, scandium nitride, ytterbium nitride, molybdenum, tungsten, hafnium, titanium, ruthenium, ruthenium oxide, chromium, chromium nitride, platinum, gold, silver, copper, aluminum, tantalum, iridium, palladium, and nickel.

### Claim 8 (depends on 6)

The piezoelectric body according to claim 6, wherein a diffusion layer is further disposed between the intermediate layer and the piezoelectric body, the diffusion layer including a substance constituting the intermediate layer and a substance constituting the piezoelectric body.

### Claim 9 (depends on 10)

A MEMS devise using the piezoelectric body according to claim 10.

### Claim 10 (depends on 1)

The piezoelectric body comprising the nitride material according to claim 1.