The ionization dynamics of SF6: a full dimensional direct ab initio dynamics study

The ionization dynamics of SF6, which plays an important role in plasma dry etching of semiconductors, has been investigated by means of full dimensio nal direct ab initio dynamics calculations. The SF6+ ion. formed by the ver tical ionization of SF6, decomposes directly into SF5+ and F without comple x formation. The dynamics calculations showed that 22% of the total availab le energy is partitioned into the relative translational mode between SF5and F. The mechanism of the ionization of SF6 and the etching of silicon by the F atom were discussed on the basis of the theoretical results.