Narrow gap reactive ion etcher-Its discharge structure and function

Summary form only given. The authors have investigated the high pressure RIE in SF/sub 6/ from the viewpoints of the RF plasma structure and function by using both numerical calculation via the relaxation continuum model and spatiotemporally resolved optical emission spectroscopy. The modeling takes account of the negative ions SF/sub 6//sup -/, SF/sub 5//sup -/, F/sup -/, the positive ion SF/sub 5//sup +/, and electrons. The system equations consist of the continuity of number density and momentum relaxation of charged particles, energy relaxation of electrons, and Poisson´s equation. The spatiotemporal structure is exhibited in terms of net ionization rate of N/sub 2//sup +/(B/sup 2//spl Sigma//sup +//sub u/), obtained experimentally and numerically for 0.5 Torr, 130 mW cm//sup -2/ and 13.56 MHz in SF/sub 6/ (90%)/N/sub 2/. The key importance of the double-layer in front of the instantaneous anode, for the purpose of the etching by both physically high energy beam ions and chemically active primary radicals is emphasized.