The Ultrasmoothness of Diamond-like Carbon Surfaces
Michael Moseler,1,2*
Peter Gumbsch,1,3
Cinzia Casiraghi,4
Andrea C. Ferrari,4
John Robertson4
The ultrasmoothness of diamond-like carbon coatings is explained
by an atomistic/continuum multiscale model. At the atomic scale,
carbon ion impacts induce downhill currents in the top layer
of a growing film. At the continuum scale, these currents cause
a rapid smoothing of initially rough substrates by erosion of
hills into neighboring hollows. The predicted surface evolution
is in excellent agreement with atomic force microscopy measurements.
This mechanism is general, as shown by similar simulations for
amorphous silicon. It explains the recently reported smoothing
of multilayers and amorphous transition metal oxide films and
underlines the general importance of impact-induced downhill
currents for ion deposition, polishing, and nanopattering.
2 Freiburg Materials Research Center, Stefan-Meier-Strasse 21, 79104 Freiburg, Germany.
3 Institute for Reliability of Systems and Components, IZBS, University of Karlsruhe, Kaiserstrasse 12, 76131 Karlsruhe, Germany.
4 Engineering Department, Cambridge University, Cambridge CB2 1PZ, UK.
* To whom correspondence should be addressed. E-mail: mos{at}iwm.fhg.de
