Influence of SnO2 over layer on nucleation and growth of diamond films on silicon substrate

The influence of tin oxide (SnO2) over layer on nucleation and growth of diamond films on silicon substrates has been investigated. In this work, the SnO2 over layer was deposited on virgin and pre-treated silicon substrates by spray pyrolysis technique and the synthesis of diamond films was accomplished using hot filament chemical vapor deposition (HFCVD) system. The deposition characteristics of diamond films were investigated by scanning electron microscopy (SEM), Raman spectroscopy and X-ray diffraction measurements (XRD). It is clearly observed that the SnO2 overlayer facilitates the nucleation and growth of diamond, although tin is a non-carbide forming element. With SnO2 overlayer, the nucleation density is found to increase irrespective of whether the substrate surface is pre-treated or not, prior to SnO2 deposition.