Effect of interfacial carbide layer on the Raman spectra in chemical-vapor deposited diamond films

Diamond films were deposited on the p-Si (100) substrates by hot filament chemical vapor deposition (HFCVD). Then, the Raman spectra of the diamond films with the substrate removed and with a carbon layer deposited on the back of the film were compared. We also investigated the characteristics of the spectra along the direction of the film thickness. The results showed that the Raman spectra were affected not only by the properties of the diamond films but also by the intcrfacial silicon carbide layer, due to the high optical transmittance of diamond. The residual stresses in the film showed a nonuniform distribution along the film thickness. However, the residual stress on the top surface of the film almost reflected the average value for the total film thickness.