Speaker
Description
Microwave Plasma Enhanced Chemical Vapour Deposition (PECVD) is a versatile technique for thin film deposition. Diamond thin films grown using Microwave PECVD have a wide range of high-tech applications including transparent windows, quantum applications of the diamond NV- centre, thermal transport layers for semiconductor devices, and nuclear battery applications. Our group has been developing microwave PECVD for the deposition of diamond thin films for quantum sensor hardware platforms and semiconductor thermal management applications [1,2]. Deposition of diamond thin films typically proceeds in a 2.54 GHz microwave plasma with a feedstock gas mixture consisting of methane with a large excess of hydrogen. (~1% CH4 / 99% H2). While negative ion formation has generally not been considered in these plasmas, both hydrogen and methane can form negative ions (metastable in the case of anionic methane [3]) and thus the prospect of negative ion formation in H2/CH4 plasmas for diamond film deposition should be considered, both theoretically and experimentally, as the detailed plasma composition is an essential component of repeatable, high-quality film formation. This talk will discuss aspects of negative ions in the context of diamond-thin-film forming plasmas, and their relevance to the deposition and applications of these films.
[1] W. Davis and M. Bradley, “Structural and Optical Analysis of NV Centers in Diamonds Synthesized by MPCVD With Controlled Nitrogen Doping Time”, IEEE Transactions on Plasma Science, 53(10), 2965-2974 (2025). DOI: https://doi.org/10.1109/TPS.2025.3591078
[2] H. Ejalonibu, G. Sarty, and M. Bradley, “The effect of step-wise surface nitrogen doping in MPECVD grown polycrystalline diamonds”, Materials Science and Engineering: B 258, 114559 (2020).
[3] A. Ramírez-Solís, J. Vigué, G. Hinojosa, and H. Saint-Martin, “Solving the CH−4 Riddle: The Fundamental Role of Spin to Explain Metastable Anionic Methane”, Phys. Rev. Lett. 124, 056001 (2020). DOI: https://doi.org/10.1103/PhysRevLett.124.056001
| Email address | "Bradley, Michael" <michael.bradley@usask.ca> |
|---|---|
| Classification/Track | Invited |
| Visitor's Visa | no |
| Classification | Plasma and negative ion diagnostics |