SiC coatings for first-wall candidate materials by R.F. sputtering

The r.f. sputtering technique was applied to form SiC coating films on first-wall candidate materials such as molybdenum, stainless steel and pyrolytic carbon at various temperatures. The coating films were examined by means of scanning electron microscopy, X-ray diffraction, Auger electron spectroscopy and roughness factor (RF) measurements. It was found that the coating films consisted of α-SiC and grew at relatively low temperatures, namely 300 °C, 600 °C and 800 °C on molybdenum, 304 stainless steel and pyrolytic carbon surfaces, respectively. The surfaces of α-SiC films grown above these temperatures were relatively smooth with small RFs in comparison with those prepared at lower temperatures. Lower temperature deposition gave rise to amorphous and rough coating films with considerably larger RFs.