THE EFFECT OF SUBSTRATE SURFACE-TEMPERATURE ON THE MORPHOLOGY AND QUALITY OF DIAMOND FILMS PRODUCED BY THE OXYACETYLENE COMBUSTION METHOD

Diamond films were synthesized using an oxyacetylene flame on a molybd enum substrate mounted on a water-cooled copper block. The morphology and quality of the synthetic diamond films produced depend on several factors including the substrate temperature, gas flow rates and their ratio, and substrate position. The substrate temperature profile was s hown to be influenced by the coolant flow rate, nozzle size, substrate position on the heat sink, substrate position in the combustion flame , and the total flow rate of mixed gas (acetylene and oxygen). In this paper, the effects of substrate temperature and nozzle size on the mo rphology and quality of diamond films are discussed. Fine-gage thermoc ouples were used to measure the temperature distribution in the substr ate during the process. Scanning electron microscopy of the produced d iamond films is used to show the variation of crystal morphology.