DYNAMIC LASER-LIGHT SCATTERING STUDIES OF DUSTY PLASMAS IN THE GASEOUS-ELECTRONICS-CONFERENCE-REFERENCE-CELL

Particle generation has been studied during reactive ion etching of ox ide wafers in CF4/CHF3 plasmas using the Gaseous Electronics Conferenc e Reference Cell. Under certain discharge process conditions, copious amounts of submicron particles form due to plasma interactions with th e oxide substrate. Particles were observed in situ by laser light scat tering and dynamic laser light scattering (DLLS). DLLS can be used to determine information about particle size, motion, and growth dynamics . DLSS measurements show process-induced dust particles confined in an electrostatic trap exhibit low-frequency oscillatory motion consisten t with charge-density-wave motion. These results are also consistent w ith the plasma dust particles forming a strongly coupled Coulomb liqui d phase. (C) 1996 American Vacuum Society.