# Fabrication of                    <i>β</i>                    -Ga                    <sub>2</sub>                    O                    <sub>3</sub>                    /air-gap structures on (010)                    <i>β</i>                    -Ga                    <sub>2</sub>                    O                    <sub>3</sub>                    by wet etching in tetramethylammonium hydroxide (TMAH)

https://mdr.nims.go.jp/datasets/7d2f8b58-a978-4d52-9171-cffbb7da7fdd

## File

- [Oshima_2025_Appl._Phys._Express_18_116501-1.pdf](https://mdr.nims.go.jp/filesets/3667f576-30cf-4fd1-8941-fde4a035aa7e/download) ([Detail](https://mdr.nims.go.jp/filesets/3667f576-30cf-4fd1-8941-fde4a035aa7e.md))

## Id

7d2f8b58-a978-4d52-9171-cffbb7da7fdd

## Local identifier



## Visibility

open_to_public

## State

published

## Created at

2025-11-25T23:24:20.440073Z

## Updated at

2025-11-26T23:30:13.342113Z

## Published at

2025-11-26T23:24:04.245590Z

## Doi



## First published url

https://doi.org/10.35848/1882-0786/ae1e59

## Date published

2025-11-01

## Recorded date published

2025-11-1

## Resource type

journal_article

## Manuscript type

vor

## Collection



## Title

- title: Fabrication of                    <i>β</i>                    -Ga                    <sub>2</sub>                    O                    <sub>3</sub>                    /air-gap
    structures on (010)                    <i>β</i>                    -Ga                    <sub>2</sub>                    O                    <sub>3</sub>                    by
    wet etching in tetramethylammonium hydroxide (TMAH)
  title_type: original
  lang: en

## Description

- description: We demonstrated the fabrication of β-Ga2O3/air-gap structures on (010)
    β-Ga2O3 substrates through sequential dry etching and crystallographic wet etching.
    Wet etching in a 25 wt% tetramethylammonium hydroxide solution at 90 °C yielded
    a lateral-to-vertical etch-rate ratio of approximately 11 when the lateral direction
    was aligned with [001]. This pronounced lateral etching enabled the undercutting
    of dry-etched β-Ga2O3 mesas to form cantilevers and air bridges extending along
    [201], which is perpendicular to [001]. This etch-only process using standard
    device-fabrication equipment offers a straightforward route for fabricating β-Ga2O3/air-gap
    structures that are promising for microelectromechanical systems.
  description_type: abstract
  lang: und

## Creator

- name: Takayoshi Oshima
  role: author
  orcid: https://orcid.org/0000-0001-8550-9735

## Contact agent



## Publisher

organization: IOP Publishing

## Managing organization



## Keyword

- subject: Ga2O3
  schema: not_defined
- subject: TMAH
  schema: not_defined
- subject: wet etching
  schema: not_defined
- subject: MEMS
  schema: not_defined

## Rights

- identifier: https://creativecommons.org/licenses/by/4.0/

## Other identifier(s)



## Data origin

- data_origin_type: other

## Embargo



## Journal

- title: Applied Physics Express
  issn: '18820778'
  volume: '18'
  issue: '11'
  article_number: '116501'

## Conference



## Related item



## Funding

- identifier: JP24K01368
  funder_name: Japan Society for the Promotion of Science

## Instrument



## Instrument operator



## Instrument managing organization



## Measurement method



## Specimen



## Chemical composition



## Structure for specimen



## Structural feature for specimen



## Specific property for specimen



## Process for specimen treatment



## Computational method



## Energy level/transition state



## Software



## Custom property



## Fileset

- id: 3667f576-30cf-4fd1-8941-fde4a035aa7e
  filename: Oshima_2025_Appl._Phys._Express_18_116501-1.pdf
  content_type: application/pdf
  size: 684066
  md5: 7bec4b625fbe9e255858e5c1dcb11fb9

## Thumbnail

fileset_id: 3667f576-30cf-4fd1-8941-fde4a035aa7e
filename: Oshima_2025_Appl._Phys._Express_18_116501-1.pdf