Published online by Cambridge University Press: 15 February 2011
Fluorinated amorphous carbon (a-C:F) films sandwiched between layers of SiO2 have been proposed as an interlayer dielectric (ILD) structure in order to enhance resistance to oxygen plasma. This study describes adhesion failure mechanisms for the sandwiched fluorinated amorphous carbon film (a-C:F) structure during oxygen plasma annealing. We have found 3 failure modes: 1) capping SiO2 layer peels off, 2) thickness reduction of a-C:F by decomposition, and 3) etching phenomena at the interface between SiO2 and a-C:F by CFx outgassing from a-C:F. The outgassed CFx radicals were stored at the interfaces and the etching of SiO2 occurred during the subsequent 150°C oxygen plasma resist removal process. Thermal decomposition of a-C:F ILD sandwiched between layers of SiO2 was performed to determine the outgassed species, as well as the thickness reduction of a-C:F.