STRESS-DISTRIBUTION AROUND THE ION-INDUCED CHANNELS IN CHEMICAL-VAPOR-DEPOSITED DIAMOND FILMS - A MICRO-RAMAN STUDY

The diamond Raman lines were examined around the He+ ion implantation- induced channels in chemical vapor deposited films over Si substrates. Several spectra from different positions around the channels, formed at different target currents, were obtained using a Raman microprobe, It is concluded that the observed shift in the diamond Raman line aris es primarily from the compressive stress. The line broadening is attri buted to the decrease in phonon lifetime, which is associated with the scattering from inhomogeneous stress distribution and from defects in the exfoliated regions. The observed correlation between the stress a nd non-diamond content at various spots suggests that the degree of co mpressive stress may he associated with the density of microcrystallin e defects produced by ion irradiation. The ion implantation-induced co mpositional transformation is also evidenced in these diamond films. ( C) 1998 John Wiley & Sons, Ltd.