# Detection limit of defect-induced strain in GaN evaluated by valence EELS and correlated structural analysis

https://mdr.nims.go.jp/datasets/97af1cbf-a370-4202-9843-7f1c33b7ec23

## File

- [HR-EELS2_revised.pdf](https://mdr.nims.go.jp/filesets/1790dcc7-eaa1-4404-a3ea-7a3d3df560ee/download) ([Detail](https://mdr.nims.go.jp/filesets/1790dcc7-eaa1-4404-a3ea-7a3d3df560ee.md))

## Id

97af1cbf-a370-4202-9843-7f1c33b7ec23

## Local identifier



## Visibility

open_to_public

## State

published

## Created at

2025-12-02T02:27:55.574307Z

## Updated at

2026-04-30T03:01:11.491392Z

## Published at

2026-07-21T23:28:47.176000Z

## Doi

https://doi.org/10.48505/nims.5945

## First published url

https://doi.org/10.1093/jmicro/dfaf034

## Date published

2026-01-01

## Recorded date published

2026-1-1

## Resource type

journal_article

## Manuscript type

accepted_manuscript

## Collection



## Title

- title: Detection limit of defect-induced strain in GaN evaluated by valence EELS
    and correlated structural analysis
  title_type: original
  lang: en

## Description

- description: Crystal defects are intrinsically linked to the electrical and optical
    properties of semiconductor materials, making their nanoscale detection essential
    across all phases (from research and development to manufacturing). Electron energy
    loss spectroscopy (EELS) in scanning transmission electron microscopy (STEM) has
    emerged as a promising technique for detecting even point defects due to the shape
    modulation in valence-loss spectra induced by defects. However, previous studies
    have primarily focused on qualitative detection, leaving the detection limit,
    i.e., the minimum detectable concentration, insufficiently explored. To experimentally
    evaluate the detection limit of defects and clarify the application scope of valence
    EELS, we prepared GaN samples with controlled defect concentrations along the
    depth direction using multi-step He-ion implantation and acquired valence-loss
    spectra at each depth. Based on the simulated depth profile of defects, we evaluated
    the detection limit from the depth at which significant modulation in the spectral
    shape was observed. The detection limit fundamentally depends on the signal-to-noise
    ratio of the valence-loss spectra. Under typical STEM conditions, the detection
    limit of defects in GaN was determined to be 0.35% (3500 ppm). Detailed structural
    analysis revealed that GaN contains implantation-induced defects and their clusters,
    and exhibits lattice strain and local disorder while retaining its wurtzite structure.
    The shape modulation in the valence-loss spectra was attributed to the indirect
    detection of defects through the surrounding strain fields.
  description_type: abstract
  lang: eng

## Creator

- name: Shunsuke Yamashita
  role: author
  organization: Sony Semiconductor Solutions Corporation
- name: Jun Kikkawa
  role: author
  orcid: https://orcid.org/0000-0003-0659-1844
  organization: National Institute for Materials Science
  department: Center for Basic Research on Materials/Advanced Materials Characterization
    Field/Electron Microscopy Group
- name: Susumu Kusanagi
  role: author
  organization: Sony Semiconductor Solutions Corporation
- name: Ichiro Nomachi
  role: author
  organization: Sony Semiconductor Solutions Corporation
- name: Ryoji Arai
  role: author
  organization: Sony Semiconductor Solutions Corporation
- name: Yuya Kanitani
  role: author
  organization: Sony Semiconductor Solutions Corporation
- name: Koji Kimoto
  role: author
  orcid: https://orcid.org/0000-0002-3927-0492
  organization: National Institute for Materials Science
  department: Center for Basic Research on Materials
- name: Yoshihiro Kudo
  role: author
  organization: Sony Semiconductor Solutions Corporation

## Contact agent



## Publisher

organization: Oxford University Press (OUP)

## Managing organization



## Keyword

- subject: Limit of detection
  schema: not_defined
- subject: Detection threshold
  schema: not_defined
- subject: Physical analysis
  schema: not_defined
- subject: Gallium nitride
  schema: not_defined
- subject: Valence electron energy loss spectroscopy (VEELS)
  schema: not_defined
- subject: Low-loss spectrum
  schema: not_defined

## Rights

- description: 'This is a pre-copyedited, author-produced version of an article accepted
    for publication in Microscopy following peer review. The version of record Shunsuke
    Yamashita, Jun Kikkawa, Susumu Kusanagi, Ichiro Nomachi, Ryoji Arai, Yuya Kanitani,
    Koji Kimoto, Yoshihiro Kudo, Detection limit of defect-induced strain in GaN evaluated
    by valence EELS and correlated structural analysis, Microscopy, 2025;, dfaf034
    is available online at: https://doi.org/10.1093/jmicro/dfaf034.'
  identifier: http://rightsstatements.org/vocab/InC/1.0/

## Other identifier(s)



## Data origin

- data_origin_type: other

## Embargo

start_date: 2025-07-22
end_date: 2026-07-22

## Journal

- title: MICROSCOPY
  issn: '20505698'

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## Fileset

- id: 1790dcc7-eaa1-4404-a3ea-7a3d3df560ee
  filename: HR-EELS2_revised.pdf
  content_type: application/pdf
  size: 1444120
  md5: 0a89bf4d718bf6a17ea0ecfbc8c89d24

## Thumbnail

fileset_id: 1790dcc7-eaa1-4404-a3ea-7a3d3df560ee
filename: HR-EELS2_revised.pdf