Predictive study of a plasma structure and function in reactive ion etcher driven by very high frequency: Validity of an extended two-dimensional relaxation continuum model

The plasma structure and physical function of a narrow gap reactive ion etcher (RIE), consisting of capacitively coupled parallel plates driven at 100 MHz, have been predicted in a proper manner by an extended relaxation continuum model including gas flow and sputtered particle transport from the substrate. Monitoring the spatiotemporal excitation rate gives validity to the use of the continuum model even at 50 mTorr under higher power condition mainly maintained by an ionization multiplication of the secondary electrons ejected from the powered electrode by ion impacts. The plasma structures are testified by comparing the two-dimensional net excitation rate of Ar(3p₅) with the experimental computerized tomography image. A nonvolatile particle transport successive to the physical etching on the substrate has been predicted in the RIE under a feed gas flow.