Deposition of Ga2O3 thin films by liquid metal target sputteringShow others and affiliations
2023 (English)In: Vacuum, ISSN 0042-207X, E-ISSN 1879-2715, Vol. 209, article id 111789Article in journal (Refereed) Published
Abstract [en]
This paper reports on the deposition of amorphous and crystalline thin films of Ga2O3 by reactive pulsed direct current magnetron sputtering from a liquid gallium target onto fused (f-) quartz and c plane (c-) sapphire sub-strates, where the temperature of the substrate is varied from room temperature (RT) to 800 degrees C. The deposition rate (up to 37 nm/min at RT on f-quartz and 5 nm/min at 800 degrees C on c-sapphire) is two to five times higher than the data given in the literature for radio frequency sputtering. Deposited onto unheated substrates, the films are X-ray amorphous. Well-defined X-ray diffraction peaks of 13-Ga2O3 start to appear at a substrate temperature of 500 degrees C. Films grown on c-sapphire at temperatures above 600 degrees C are epitaxial. However, the high rocking curve full width at half maximum values of X2.4-2.5 degrees are indicative of the presence of defects. A dense and void-free microstructure is observed in electron microscopy images. Composition analysis show stoichiometry close to Ga2O3 and no traces of impurities. The optical properties of low absorptance (<1%) in the visible range and an optical band gap of approximately 5 eV are consistent with the data in the literature for Ga2O3 films produced by other deposition methods.
Place, publisher, year, edition, pages
Elsevier, 2023. Vol. 209, article id 111789
Keywords [en]
Gallium oxide, Thin films, Magnetron sputtering, Liquid metal target
National Category
Condensed Matter Physics Inorganic Chemistry
Identifiers
URN: urn:nbn:se:uu:diva-497102DOI: 10.1016/j.vacuum.2022.111789ISI: 000923210100001OAI: oai:DiVA.org:uu-497102DiVA, id: diva2:1738993
2023-02-232023-02-232023-02-23Bibliographically approved