{
  "abstract": "Atomic layer epitaxy of high quality κ-Ga2O3 thin films on c-plane sapphire using atomic layer deposition (ALD) offers new opportunities for optoelectronics and power electronics. However, the effects of increasing the number of cycles to increase the κ-Ga2O3 film thickness in the range of 20–100 nm are still unknown. Herein, we study the ALD of the epitaxial (001) κ-Ga2O3 thin film as a function of its thickness by varying the number of cycles from 400 to 2000. Above 20 nm, the epitaxial growth of κ-Ga2O3 thin films with a low surface roughness is preserved with the following relationship: κ-Ga2O3 (001)‖α-Al2O3 (0001), κ-Ga2O3 [010]‖α-Al2O3 [10−10], and κ-Ga2O3 [100]‖α-Al2O3 [11−20]. However, relaxation processes of the epitaxial strain occur, resulting in the formation of multiple rotational domains. Using thermal annealing, a full phase conversion from κ-Ga2O3 to β-Ga2O3 is shown, regardless of the thickness of the as-deposited film. The annealed Ga2O3 thin films grown using 400 cycles remarkably exhibit low surface roughness along with the following epitaxial relationship: β-Ga2O3 (−201)‖α-Al2O3 (0001) and β-Ga2O3 [010]‖α-Al2O3 [10−10]. In contrast, the annealed Ga2O3 thin films grown using 2000 cycles have a higher structural disorder induced by the initial presence of multiple rotational domains. Furthermore, we reveal that the carbon contamination remains negligible both before and after thermal annealing. Eventually, Al/Ga inter-diffusion processes in the proximity of the interface are shown by X-ray photoelectron spectroscopy and transmission electron microscopy after thermal annealing, resulting in the formation of an O-rich region.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": null,
  "author_total": 13,
  "authors": [
    {
      "name": "Andy Séguret"
    },
    {
      "name": "Ilyass Jellal"
    },
    {
      "name": "Hervé Roussel"
    },
    {
      "name": "Isabelle Gélard"
    },
    {
      "name": "Sonia Ortega Murillo"
    },
    {
      "name": "Laetitia Rapenne"
    },
    {
      "name": "Eirini Sarigiannidou"
    },
    {
      "name": "Fabrice Wilhelm"
    },
    {
      "name": "Andrei Rogalev"
    },
    {
      "name": "Marty Volant"
    },
    {
      "name": "Hanako Okuno"
    },
    {
      "name": "Eva Monroy"
    },
    {
      "name": "Vincent Consonni"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/eq1c4cxcmnbcd.bib",
  "cited_by": 0,
  "doi": "10.1039/d6tc01146b",
  "fulltext_url": null,
  "id": "eq1c4cxcmnbcd",
  "issns": [
    "2050-7526",
    "2050-7534"
  ],
  "landing_url": "https://hal.science/hal-05797161v1",
  "language": "en",
  "licence": "CC-BY-NC-4.0",
  "licence_label": "CC BY-NC 4.0",
  "licence_source": "article",
  "licence_url": "https://creativecommons.org/licenses/by-nc/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "hal",
      "0.chim"
    ],
    [
      "hal",
      "1.chim.mate"
    ],
    [
      "openalex",
      "2504|Ga2O3 and related materials"
    ]
  ],
  "openalex": "W7171491449",
  "pdf_url": "https://hal.science/hal-05797161/document",
  "pmcid": null,
  "pmid": null,
  "published": "2026-07-28",
  "publisher": "Royal Society of Chemistry",
  "ris": "https://research.draconitic.com/paper/eq1c4cxcmnbcd.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:17:56Z",
      "native_id": "hal-05797161",
      "source": "hal",
      "url": "https://hal.science/hal-05797161v1"
    }
  ],
  "subjects": [
    {
      "field": "chemistry",
      "origin": "hal:1.chim.mate",
      "subfield": "materials-polymers"
    }
  ],
  "title": "ALD grown (001) κ-Ga2O3 epitaxial thin films on c-plane sapphire: influence of thickness and thermal annealing",
  "title_text": "ALD grown (001) κ-Ga2O3 epitaxial thin films on c-plane sapphire: influence of thickness and thermal annealing",
  "type": "peer-reviewed",
  "updated_at": "2026-10-30T12:17:56Z",
  "url": "https://research.draconitic.com/paper/eq1c4cxcmnbcd",
  "venue": "Journal of Materials Chemistry C",
  "versions": []
}