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 BCl sub 3. Although it was expected that the Ar metastable state would affect the degree of BCl sub 3 dissociation, the mechanism uncovered using in situ diagnostics had not been considered previously: superelastic collisions between Ar metastables and electrons produce hot electrons capable of dissociating BCl sub 3 more efficiently. By contrast, direct dissociative energy transfer from Ar metastables to BCl sub 3 is unimportant. This mechanism leads to a narrow concentration range over which the dissociative excitation of BCl sub 3 is increased 10-fold relative to the pure BCl sub 3 discharge.