SCALING LAWS FOR RADIO-FREQUENCY GLOW-DISCHARGES FOR DRY ETCHING

Parametric studies of parallel plate radio frequency (rf) glow discharges have been performed using an efficient numerical scheme developed for solving fluid model representations of glow discharges. Simple scaling laws for internal discharge parameters have been extracted from detailed simulations of discharges in Ar and SF6. These laws scale charged particle concentrations, charged particle fluxes, the electron temperature, and sheath voltages on the measured rf power, the rf voltage, and the rf current. These laws are relatively insensitive to the details of the gas composition and electrode surface conditions. Measurements of charged particle concentrations using a recently developed tuned Langmuir probe technique provide experimental justification for some of the scaling laws. Such laws allow for the rapid determination of internal discharge parameters and can be used for systemizing process design, for process control, and for transferring a process from one system to another. Results of response surface methodology experiments can be scaled on inferred internal discharge parameters to elucidate etching mechanisms. © 1990, American Vacuum Society. All rights reserved.