# Investigation of Deep States in GaN Metal-Oxide-Semiconductor Interfaces

https://mdr.nims.go.jp/datasets/4a8e7461-ecc1-49c7-b3e7-5b8df642a9e0

## File

- [Irokawa_2026_ECS_J._Solid_State_Sci._Technol._15_055002.pdf](https://mdr.nims.go.jp/filesets/73b099f7-414e-475f-9f4b-bb7d924f27e2/download) ([Detail](https://mdr.nims.go.jp/filesets/73b099f7-414e-475f-9f4b-bb7d924f27e2.md))

## Id

4a8e7461-ecc1-49c7-b3e7-5b8df642a9e0

## Local identifier



## Visibility

open_to_public

## State

published

## Created at

2026-05-12T23:12:01.545626Z

## Updated at

2026-05-13T01:14:20.090062Z

## Published at

2026-05-13T03:28:43.222607Z

## Doi



## First published url

https://doi.org/10.1149/2162-8777/ae6689

## Date published

2026-05-01

## Recorded date published

2026-5-1

## Resource type

journal_article

## Manuscript type

vor

## Collection



## Title

- title: Investigation of Deep States in GaN Metal-Oxide-Semiconductor Interfaces
  title_type: original
  lang: en

## Description

- description: 'We previously reported a powerful method to improve dielectric/GaN
    interface properties: the dummy SiO2 process [Y. Irokawa et al., ECS J. Solid
    State Sci. Technol. 13, 085003 (2024)]. Here, GaN metal-oxide-semiconductor (MOS)
    interfaces prepared with this process were investigated using a sub-bandgap photo-assisted
    capacitance–voltage technique. GaN MOS interfaces were previously revealed to
    have deep states, and the dummy process was expected to reduce the number of deep
    states through its interface modification process. However, the deep state densities
    in Al2O3/GaN MOS interfaces after the dummy process did not substantially change
    compared with those in devices fabricated without the dummy process. Meanwhile,
    we recently observed oxygen atoms in positions proximate to nitrogen sites in
    MOS interface regions, with the GaN crystal maintaining the same structure [J.
    Uzuhashi et al. ECS J. Solid State Sci. Technol. 14, 085001 (2025)]. We therefore
    performed first-principles calculations and found that, under certain circumstances,
    a pair of oxygen atoms replacing nitrogen atoms in GaN created deep states in
    the bandgap, with slight displacements, similar to DX centers; this substitution
    could be one of the origins of deep states in GaN MOS interfaces.'
  description_type: abstract
  lang: und

## Creator

- name: Yoshihiro Irokawa
  role: author
  orcid: https://orcid.org/0000-0002-6531-4356
- name: Mamoru Usami
  role: author
  orcid: https://orcid.org/0009-0002-3188-7380
- name: Jun Uzuhashi
  role: author
  orcid: https://orcid.org/0000-0003-2023-8158
- name: Tadakatsu Ohkubo
  role: author
  orcid: https://orcid.org/0000-0003-3548-1951
- name: Toshihide Nabatame
  role: author
  orcid: https://orcid.org/0000-0002-5973-0230
- name: Yasuo Koide
  role: author
  orcid: https://orcid.org/0000-0001-8321-9822

## Contact agent



## Publisher

organization: The Electrochemical Society

## Managing organization



## Keyword

- subject: GaN
  schema: not_defined

## Rights

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

## Other identifier(s)



## Data origin

- data_origin_type: other

## Embargo



## Journal

- title: ECS Journal of Solid State Science and Technology
  issn: '21628769'
  volume: '15'
  issue: '5'
  article_number: '055002'

## Conference



## Related item



## Funding

- identifier: JPJ009777
  funder_name: Ministry of Education, Culture, Sports, Science and Technology, Japan
- identifier: 23K03949
  funder_name: JSPS KAKENHI

## 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: 73b099f7-414e-475f-9f4b-bb7d924f27e2
  filename: Irokawa_2026_ECS_J._Solid_State_Sci._Technol._15_055002.pdf
  content_type: application/pdf
  size: 2133888
  md5: 9da37650785d773fc75f518bc14dc2f3

## Thumbnail

fileset_id: 73b099f7-414e-475f-9f4b-bb7d924f27e2
filename: Irokawa_2026_ECS_J._Solid_State_Sci._Technol._15_055002.pdf