The role of dissociative and ionizing electron-molecule collisions in low-temperature processing plasmas

We have been studying the dissociative excitation and the ionization of several important processing plasma constituents such as the halogen-containing molecules SF6, CF4, NF3, CCl2F2, BCl3, the complex Si-organic compounds TEOS (tetra-ethoxysilane) and HMDSO (hexa-methyldisiloxane) and various free radicals (CF3, CF2, CF, NF2, NF, SiF3, SiF2, SiF and SO) using a variety of electron collisions techniques. More recently, experiments to study the formation of neutral ground state dissociation fragments using laser-induced fluorescence techniques are also under way. Several specific examples will be discussed in detail in this presentation and an attempt is being made to correlate the results of the collision physics experiments to the fundamental processes relevant in the processing plasmas. (author)