Design and Development of Novel Remover for Cu/Porous Low-k Interconnects
At 32nm and below the integration of extreme low-k dielectrics (ELK) with a permittivity of 2.2 or lower will require considerable process optimization at etch and clean to maintain critical dimension (CD) and effective k. Of equal concern is the impact on yield and reliability of lateral Cu etch or incomplete removal of copper oxides (CuOx) during post etch residue (PER) cleaning. These are not new issues but the challenges of solving them in the presence of ELK’s are considerable not least in relation to the question of selectivity towards “damaged low k” interfaces, often described as densified or C depleted layers.
Paul Mertens, Marc Meuris and Marc Heyns
T. Suzuki et al., "Design and Development of Novel Remover for Cu/Porous Low-k Interconnects ", Solid State Phenomena, Vols. 145-146, pp. 315-318, 2009