Simultaneous interaction of methyl radicals and atomic hydrogen with amorphous hydrogenated carbon films

The simultaneous interaction of methyl radicals (CH3) and atomic hydrogen ( H) with the surface of amorphous hydrogenated carbon (a-C:H) films is inves tigated by using quantified radical beam sources. The growth and/or erosion of the films during the interaction of the H and CH3 radical beam with the surface is monitored by means of in situ real-time ellipsometry at a subst rate temperature of 320 K. Interaction with the CH3 beam alone results in a slow growth rate corresponding to a sticking coefficient for CH3 of simila r to 10(-4). Simultaneous interaction of an atomic hydrogen beam and the CH 3 radical beam with the surface results in a sticking coefficient for CH3 o f similar to 10(-2). A microscopic modeling of this synergistic growth yiel ds a cross section of 3.8 Angstrom (2) for CH3 adsorption at a dangling bon d, created by abstraction of surface bonded hydrogen due to impinging atomi c hydrogen. The cross section for the abstraction of surface bonded hydroge n by impinging CH3 radicals is 1.5 x 10(-3) Angstrom (2). (C) 2001 American Institute of Physics.