Heterogeneous recombination of atomic bromine and fluorine

Recombination coefficients (γ) of Br and F atoms have been measured for crystalline Si, quartz, photoresist, anodized aluminum, poly-Si, WSi x , tungsten and stainless steel surfaces for a range of temperatures. The γ Br and γ F values are compared to our previously reported measurements of γ Cl [G. P. Kota, J. W. Coburn, and D. B. Graves, J. Vac. Sci. Technol. A 16, 270 (1998)]. In general, the Br-, Cl- and F-atom recombination coefficients decrease as the surface temperature increases. The γ Br values are similar to the γ Cl values for the various surfaces. At room temperature, γ Br is highest (>0.4) for stainless steel and tungsten, moderate (0.1–0.4) for poly-Si, WSi x and anodized Al, and lowest (