Space-time resolved kinetics of mixed rare-gas-attaching gas plasmas

Because plasma processing recipes are usually determined empirically, it is desirable to develop methods for isolating kinetic mechanisms in discharges through gas mixtures. In this manuscript, we show how space-time resolved measurements of plasma-induced emission and laser-induced fluorescence intensities are used to distinguish between electronic, ionic, and neutral mechanisms for excited-state production in radio frequency discharges containing Ar and BC1₃. Although it was expected that the Ar metastable state would affect the degree of BC1₃dissociation, the mechanism uncovered using in situ diagnostics had not been considered previously: a two-step process involving Ar metastables and slow electrons leads to enhanced dissociation of BC1₃. By contrast, direct dissociative energy transfer from Ar metastables to BC1₃is unimportant. This mechanism leads to a narrow concentration range over which the dissociative excitation of BC1₃is increased tenfold relative to the pure BC1₃discharge.