Microstructural characterization and thermal stability of He charged amorphous silicon films prepared by magnetron sputtering in helium

Sputtering of silicon in a Helium magnetron discharge has been reported as a bottom-up procedure to obtain amorphous Si films containing high amounts of gas-filled nanopores. Here we compare the microstructure and composition of Si–He nanocomposite films deposited by magnetron sputtering (MS) with 4...

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Detalles Bibliográficos
Autores: Fernández, Asunción, Sauvage, T., Diallo, B., Hufschmidt, D., Jiménez de Haro, María del Carmen, Montes, O., Martínez-Blanes, José M., Caballero-Hernández, J., Godinho, Vanda, Ferrer, F. J., Ibrahim, S., Brault, P., Thomann, A. L.
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2023
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/334938
Acceso en línea:http://hdl.handle.net/10261/334938
https://api.elsevier.com/content/abstract/scopus_id/85151287194
Access Level:acceso abierto
Palabra clave:4He and 3He charged Si films
IBA analysis
Magnetron sputtering in helium
Microstructural characterization
Nanopores and nanobubbles
Thermal stability for He release
Descripción
Sumario:Sputtering of silicon in a Helium magnetron discharge has been reported as a bottom-up procedure to obtain amorphous Si films containing high amounts of gas-filled nanopores. Here we compare the microstructure and composition of Si–He nanocomposite films deposited by magnetron sputtering (MS) with 4He in DC or RF and 3He in RF operation modes. Electron microscopy (SEM and TEM), X-ray diffraction (XRD) and ion beam analysis (IBA) have been used to analyze the films and to investigate the in-situ and ex-situ thermal evolution. Depending on deposition conditions different in depth compositions, nanopore size and shape distributions, porosity and He content could be obtained. The presence of impurities (i.e. oxygen) has shown to promote He diffusivity reducing He accumulation. The start temperature of He-release varied in the range 473–723 K without films crystallization. Films grown in RF mode reached contents of 32 and 29 at% of 4He and 3He and were respectively stable up to 573 and 723 K both in vacuum and under inert gas flow. In-situ p-EBS (proton Elastic Back Scattering) allowed monitoring the He release accompanied by blistering/delamination effects visualized by SEM. These results show the potentiality of annealing to hold nano-porous structures after liberation of trapped gas.