Recent advances in hollow cathode technology for plasma-enhanced ALD—plasma surface modifications for aluminum and stainless-steel cathodes

Kenneth Scott Alexander Butcher*, Vasil Georgiev, Dimka Georgieva

*Corresponding author for this work

    Research output: Contribution to journalArticlepeer-review

    4 Citations (Scopus)
    159 Downloads (Pure)

    Abstract

    Recent designs have allowed hollow cathode gas plasma sources to be adopted for use in plasma-enhanced atomic layer deposition with the benefit of lower oxygen contamination for non-oxide films (a brief review of this is provided). From a design perspective, the cathode metal is of particular interest since—for a given set of conditions—the metal work function should determine the density of electron emission that drives the hollow cathode effect. However, we found that relatively rapid surface modification of the metal cathodes in the first hour or more of operation has a stronger influence. Langmuir probe measurements and hollow cathode electrical characteristics were used to study nitrogen and oxygen plasma surface modification of aluminum and stainless-steel hollow cathodes. It was found that the nitridation and oxidation of these metal cathodes resulted in higher plasma densities, in some cases by more than an order of magnitude, and a wider range of pressure operation. Moreover, it was initially thought that the use of aluminum cathodes would not be practical for gas plasma applications, as aluminum is extremely soft and susceptible to sputtering; however, it was found that oxide and nitride modification of the surface could protect the cathodes from such problems, possibly making them viable.

    Original languageEnglish
    Article number1506
    Pages (from-to)1-26
    Number of pages26
    JournalCoatings
    Volume11
    Issue number12
    DOIs
    Publication statusPublished - Dec 2021

    Bibliographical note

    © 2021 by the authors. Licensee MDPI, Basel, Switzerland. Version archived for private and non-commercial use with the permission of the author/s and according to publisher conditions. For further rights please contact the publisher.

    Keywords

    • Atomic layer deposition
    • Electron emission
    • Hollow cathode
    • Metal work function
    • Plasma
    • Plasma technology
    • Plasma treatment
    • Thin film deposition

    Fingerprint

    Dive into the research topics of 'Recent advances in hollow cathode technology for plasma-enhanced ALD—plasma surface modifications for aluminum and stainless-steel cathodes'. Together they form a unique fingerprint.

    Cite this