Fabrication of β-Ga <sub>2</sub> O <sub>3</sub> /air-gap structures on (001) β-Ga <sub>2</sub> O <sub>3</sub> using HCl gas etching
β-Ga2O3/air-gap structures were fabricated on (001) substrates via crystallographic etching with HCl gas. Etching at 650 °C under an HCl partial pressure of 250 Pa resulted in a vertical etch rate of 0.10 μm/min on the (001) plane and a lateral etch rate of 0.70 μm/min along the < 010 > direction. This high orthogonal etching anisotropy enabled the formation of β-Ga2O3/air-gap structures – such as cantilevers and air bridges – without the need for wafer bonding or transfer processes. This straightforward technique, compatible with commonly used (001) substrates, holds promise for the integration of β-Ga2O3-based microelectromechanical systems (MEMS) and power electronic devices.
Authors
- Takayoshi Oshima (ORCID: https://orcid.org/0000-0001-8550-9735)
- Yuichi Oshima (ORCID: https://orcid.org/0000-0001-8293-4891)
Institutions
- National Institute for Materials Science (JP)
Publication Details
- Journal
- Science and Technology of Advanced Materials Methods
- Published
- 2025-09-01
- DOI
- https://doi.org/10.1080/27660400.2025.2554046
- Citations
- 1
- Primary Topic
- Ga2O3 and related materials
- Type
- article
- Field-Weighted Citation Impact
- 0.43
Funders
- Japan Society for the Promotion of Science