Electron collisions with processing plasma constituents

The author is studying the electron-impact dissociation of NF₃, CF₄, SF₆, BCl₃, and CCl₂F₂, which are among in the most commonly employed reactive constituents of etchant gas plasmas. The objective is to determine absolute cross sections and appearance potentials for the formation of the various radiating, metastable, and neutral ground-state fragments that are produced by controlled electron-impact dissociation of these molecules. Experimental techniques include electron and optical emission spectroscopy, mass spectroscopy, time-of-flight (TOF), and laser-induced-fluorescence techniques. Results on molecular emissions in the near ultraviolet region of the the optical spectrum are reported. These include the emission of the BCl A → X band system from BCl₃, the CCl A → X and CCl⁺ A → X band systems from CCl₂F₂, and continuous UV emissions following dissociative electron impact on SF₆ and NF₃.