Studies of chemiluminescence accompanying fluorine atom etching of silicon

Abstract

A broad continuum centered at 632 nm is present during the etching of silicon by F atoms, and in the flowing afterglow of an SiF₄ discharge. A study of this feature and other spectra in pulsed and continuous discharges provides strong evidence that SiF_x radicals (apparently SiF₂) are formed as primary products when Si is gasified by atomic fluorine. The 632‐nm emission is tentatively ascribed to the reaction processes (1) SiF₂+F (or F₂) → SiF^*₃ and (2) SiF^*₃ → SiF₃+hν_continuum.