Improvement in surface roughness of nitrogen-implanted glassy carbon by hydrogen doping

We have demonstrated that hydrogen doping (similar to30 at.%) improves the surface roughness of N-implanted glassy carbon (GC). Prior to nitrogen implantation, D-2(+) molecular ions with energy of 10 keV were implanted in GC to a dose of 6 X 10(17) D cm(-2). Part of the doped hydrogen atoms is released by 100-keV N-2(+) implantation, but hydrogen incorporation occurs simultaneously. Consequently, the concentration of hydrogen in the N-implanted layer exceeds 20 at.% at any N implantation dose. For hydrogen-doped GC, surface roughening due to N implantation was not observed in all cases examined. This indicates that hydrogen incorporation suppresses the surface roughening. A possible mechanism for the surface roughening and its suppression by hydrogen doping is discussed in terms of chemical bonding and structure in the N-implanted layer. (C) 2003 Elsevier Science B.V. All rights reserved.