Seminar : prof. Rajesh GANESAN
- https://nism.unamur.be/events/seminar-prof-rajesh-ganesan
- Seminar : prof. Rajesh GANESAN
- 2020-07-06T11:00:00+02:00
- 2020-07-06T12:00:00+02:00
- « Highly tetrahedral amorphous carbon films by HiPIMS »
- When Jul 06, 2020 from 11:00 AM to 12:00 PM (Europe/Brussels / UTC200)
- Where Physics and Chemistry Department - auditorium CH01
- Contact Name Emile Haye
-
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Rajesh GANESAN
The University of Sydney, NSW 2006 Australia
High-power impulse magnetron sputtering (HiPIMS) is used to deposit amorphous carbon (a-C) thin films with sp3 fractions higher than 70%. Increasing the pulse length results in a transition from conventional HiPIMS deposition to a “mixed-mode” in which an arc triggers on the target surface, resulting in excessive generation of carbon ions. In mixed mode HiPIMS operation, short-lived cathode spots form in the magnetic racetrack and produce large numbers of carbon ions. The chemical and physical properties of the deposited a-C films vary in a consistent manner, showing a high tetrahedral character only for long pulses, demonstrating that mixed-mode deposition is the source of the high carbon ion flux. Varying the substrate bias reveals an “energy window” effect, where the sp3 fraction of the films is greatest for a substrate bias around −100V and decreases for higher or lower bias values. In the absence of bias, the films' properties show little dependence on the pulse length, showing that energetic ions are the origin of the highly tetrahedral character.
