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 mono-fluoride, –(CF)_n–, film near the surface of GC is considered to be grown onto the GC surface above 400 °C 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 °C. Although GC is apparently etched by ClF₃ over 600 °C, the etch rate of GC is much lower than that of SiC and quartz.