Effective post-etch residue removal on low-K films using single wafer processing

Integrating copper and low-k dielectrics remains challenging but necessary to semiconductor processing progress. Removing post-etch residues from copper and low-k materials is a critical part of this effort. The initial step in this work was to investigate the compatibility of low-k dielectrics with different residue removal chemistries in a static beaker setup. The chemical compatibility of the materials was evaluated by observing changes in thickness and refractive index as measured with spectroscopic ellipsometry. Next we tested residue removal efficiency of several of the chemistries on dry-etched 200mm wafers. The wafers were processed in a Semitool® Capsule single-wafer processing chamber. Residue removal capability and material compatibility were studied using X-section SEM.