Mechanism of the Interaction between F Atoms and SiCF3 Groups on the Low-κ Dielectric Surface

Abstract

The possible reactions between thermal F atoms and SiCF3 surface groups are simulated using density functional theory. These reactions constitute a part of the multistage mechanism by which SiOCH films are damaged and etched by fluorine radicals. The results of simulation demonstrate that a probable channel for removing carbon-containing compounds from the surface is the generation of volatile CF3 radicals with the simultaneous formation of SiF surface groups. The probability of the separation of a CF4 molecule is low due to a forbidding activation barrier of ~1.4 eV.