Enhancement of Iodine Adsorption Using I_2 Plasma for Seedless Catalyst-Enhanced CVD of Copper

摘要

The promotion of iodine adsorption on copper diffusion barrier metal of TiN using I_2 plasma for the seedless catalyst-enhanced chemical vapor deposition (CECVD) of copper is presented. Iodine atoms, catalytic surfactant, were not sufficiently absorbed on TiN with a simple exposure to ethyl iodide (C_2H_5I) vapor. Alternatively an I_2 plasma treatment improved iodine adsorption on TiN films and even on an oxide film of SiO_2. In addition, the iodine adatoms on TiN and SiO_2 also showed the catalytic surfactant effect on the following metallorganic CVD of copper. The improvement in iodine adsorption on the TiN substrate was confirmed with secondary-ion mass spectroscopy analysis. By utilizing the I_2 plasma treatment directly on the copper diffusion barrier metal, the bottom-up filling of copper on submicrometer features was also realized in the CECVD of copper without preparing copper seed layers.