The CVD Diamond Nucleation Mechanism on Si Overlaid with Sp2 Carbon

Rudder et al. [1] observed heavy (>109 cm-2) diamond nucleation on unscratched Si wafers overlaid with carbon fibers during CVD growth. We demonstrate that the nucleation occurs on the edges of etch pits and carbon-rich particles resulting from reaction between the fibers and the substrate. Both the etch pits and the particles satisfy what we consider to be two necessary conditions for “spontaneous” nucleation; a carbon-saturated surface and high energy sites (unsatisfied valencies) at edges and steps.