Growth of Nano Crystalline Diamond on Silicon Substrate Using Different Etching Gases by HFCVD

We investigate the effects of etching gases on the synthesis of nano crystalline diamonds grown on silicon substrate at the substrate temperature of 550 oC and the reaction pressure of 4 kPa by hot filament chemical vapor deposition method, in which CH₄ and H₂ act as a source and diluting gases, respectively. N₂, H₂, and NH₃ were used as the etching gases, respectively. Results show that the optimum conditions can be obtained only for the case of H₂ gas. The crystal morphology and crystallinity of the samples have been examined by scanning electron microscopy and X-ray diffraction, respectively.