Approaching ultrathin VO2films on sapphire (001) substrates by biased reactive sputtering: Characteristic morphology and its effect on the infrared-light switching

Ultrathin VO2 films with insulator-metal transition (IMT) were successfully fabricated on sapphire (001) substrates by utilizing radio frequency-biased reactive sputtering. We realized a 6 nm-thick VO2 film that shows resistance change over 2 orders of magnitude. Microscopic observations combined wi...

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Detalhes bibliográficos
Autores: Okimura, Kunio, Sakai, Joe, Kuwahara, Masashi, Zaghrioui, Mustapha, Uehara, Yoichi
Formato: artículo
Estado:Versión publicada
Fecha de publicación:2021
País:España
Recursos:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/264197
Acesso em linha:http://hdl.handle.net/10261/264197
Access Level:acceso abierto
Palavra-chave:Thin films
Thermal effects
Atomic force microscopy
Crystal structures
X-ray diffraction
Sputter deposition
Oxides
Raman spectroscopy
Scanning electron microscopy
Tensile stress
Descrição
Resumo:Ultrathin VO2 films with insulator-metal transition (IMT) were successfully fabricated on sapphire (001) substrates by utilizing radio frequency-biased reactive sputtering. We realized a 6 nm-thick VO2 film that shows resistance change over 2 orders of magnitude. Microscopic observations combined with energy dispersive x-ray analyses revealed characteristic networking morphology in VO2 films with thickness up to around 10 nm. It was found through micro-Raman analyses that a 30 nm-thick film possessed flat surface and ordered lattice with strong in-plane tensile stress. We evaluated the thickness dependence of optical switching performance for infrared-light. The results suggest that the thickness of the VO2 films should be carefully selected for realizing required performances of optical switching, which depends on not only IMT but also characteristic morphological aspects.