abstract
There exists a great necessity for in situ nanoscale characterization of surfaces and thin films during plasma treatments. To address this need, the current approaches rely on either "post mortem" sample microscopy or in situ optical methods. The latter, however, lack the required nanoscale spatial resolution. In this paper, we propose scanning near-field microwave microscopy to monitor plasma-assisted processes with a submicron spatial resolution. In our approach, a plasma environment with an object of interest is separated from the near-field probe and the rest of the microscope by a SiN membrane of a few tens of nanometer thickness, and the imaging is performed through this membrane. As a proof of concept, we were able to monitor gradual transformations of carbon nanotube films upon plasma-induced oxidation by a low-pressure air plasma. In the implemented approach with the near-field probe in contact with the membrane, the plasma processing should be interrupted during imaging to preserve the membrane integrity. Possible solutions to achieve in situ real-time imaging during plasma conditions are discussed.
keywords
ELECTRON-BEAM
subject category
Physics
authors
Tselev, A; Fagan, J; Kolmakov, A
our authors
Alexander Tselev
Principal Researcheracknowledgements
AT acknowledges the CICECO-Aveiro Institute of Materials POCI-01-0145-FEDER-007679 (Ref. No. FCT UID/CTM/50011/2013), financed by national funds through the FCT/MEC and when applicable co-financed by FEDER under the PT2020 Partnership Agreement. The authors are thankful to Dr. P. Maksymovych (ORNL), Dr. N. Zhitenev, Dr. J. J. Kopanski, Dr. S. J. Stranick, and Dr. K. Siebein (all at NIST) for constructive feedback on the manuscript and help with equipment.