Thermal desorption behavior of AlF3 formed on Al 2O3

Thermal desorption behaviors of the AlF3 layer formed on A1 2O3 in the sample temperature range from TS = 300 to 930 K have been studied using molecular beam mass spectrometry combined with a time-of-flight (TOF) technique. Fluorine atoms were detected as the desorbed species at sample temperatures of Ts = 625 to 850 K and the intensity was found to be peaked at Ts = 750 K. AlF2 species whose translational temperature Ttr is approximately 100 K lower than TS were also detected as desorbed species above T s = 850 K and the intensity increased exponentially as Ts was raised. Based on these results, the desorption behavior of AlF3 species is discussed.