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Porträt Dr. Bischoff, Lothar; FWIZ-N

Dr. Lothar Bischoff

Nanostructures by focused electrons and ions
Liquid Metal Alloy Ion Sources
Ion Induced Nanostructures
l.bischoffAthzdr.de
Phone: +49 351 260 2866
+49 351 260 2963

Investigation of conducting nanostructures on ta-C films made by FIB lithography

DFG – project BI 508 / 13-1      04/2010 – 08/2013   Dr. Peter Philipp

Tetrahedral amorphous carbon (ta-C) films with high sp3 content produced by mass filtered vacuum arc deposition were modified by Ga+ FIB irradiation.

Surface swelling occurs as a function of fluence, caused by ion induced conversion of sp3 to sp2 hybridized carbon atoms. A model for diamond swelling was applied to ta-C films to estimate the swelling for fluences up to 1 x 1016 cm-2. For higher fluences data from TRIDYN simulations were included due to sputtering in a good agreement with the experiments.

Van der Pauw structures were produced by means of Ga+ FIB lithography. A decrease of the sheet resistance with increasing fluences due to the evolution of graphitic regions was observed. The lowest value of 290 Ω/ was achieved at 1.6 x 1017 cm-2.

Additionally, conducting graphitic wires were produced (length: 10 µm, width: 300 nm to 5 µm). The wire resistivity was measured within 130 kΩ (5 µm width) and 3 GΩ (300 nm width).

Ion induced graphitization of ta-C films by FIB offers prospective applications in nano technology to fabricate conductive nanostructures in an insulating thin film.


Contact

Dr. Lothar Bischoff

Nanostructures by focused electrons and ions
Liquid Metal Alloy Ion Sources
Ion Induced Nanostructures
l.bischoffAthzdr.de
Phone: +49 351 260 2866
+49 351 260 2963