To evaluate potential solutions for reducing the damage to ultra low-k dielectrics during photoresist stripping in advanced interconnect technology, we have investigated the mechanisms of interactions between remote H-2, D-2 and N-2 discharges and porous organo-silicate materials. Extended sub-surface modifications take place in high carbon-content organo-silicates, whereas silica-rich dielectrics show negligible chemical damages during the same treatments. The nature of plasma/dielectric interactions depends primarily on the organic fraction of the ULK material. Methyl groups in silica-rich organosilicates withstand the interaction with the plasma species. Conversely, large organic compounds in carbon-rich dielectrics experience cleavage reactions leading to volatile hydrocarbon formation and compositional changes. For conditions where stripping-induced damage is introduced, the effects scale with the substrate temperature in the range 200 degrees C-300 degrees C. The permeation of the ULK material by remote plasma species depends on its porosity. (c) 2007 Elsevier B.V. All rights reserved.