EXPERIMENTAL APPROACH TO THE MECHANISM OF THE NEGATIVE BIAS ENHANCED NUCLEATION OF DIAMOND ON SI VIA HOT-FILAMENT CHEMICAL-VAPOR-DEPOSITION

The mechanism of the negative bias enhanced nucleation of diamond on s ilicon has been studied by a set of experiments using hot filament che mical vapor deposition. Nucleation enhancement was achieved for experi mental configurations either with or without the application of a nega tive bias to the mirror-polished Si substrates. The obtained nucleatio n density ranged from 10(8) to 10(10) cm(-2). The as-deposited films w ere characterized by scanning electron microscopy and Raman spectrosco py. Our results demonstrate that the electron emission from the diamon d coating the substrate holder, which is speculated to greatly increas e the concentration of atomic hydrogen and dissociated hydrogen radica ls on/near the substrate surface is responsible for the nucleation enh ancement during the bias pretreatment. (C) 1996 American Institute of Physics.