A study on the reaction between chlorine trifluoride gas and glass-like carbon

The reaction between glass-like carbon (GC) and chlorine trifluoride (ClF3) gas was investigated with weight measurements, surface analysis, and gas desorption measurements, where the ClF3 gas is used for the in situ cleaning of tubes in silicon-related fabrication equipment. From Auger electron spectroscopy and X-ray photoelectron spectroscopy measurements, a carbon monofluoride, –(CF)n–, film near the surface of GC is considered to be grown onto the GC surface above 400 8C by the chemical reaction with ClF3, and this thickness of the fluoride film depends on the temperature. The grown fluoride film desorbs by annealing in a vacuum up to 600 8C. Although GC is apparently etched by ClF3 over 600 8C, the etch rate of GC is much lower than that of SiC and quartz.