Low-k fluorinated amorphous carbon interlayer technology for quarter micron devices

We have developed a new interlayer technology that attain 50% reduction in capacitance and keep good process compatibility with current Chemical Mechanical Polishing (CMP) based multi-level metallization (MLM) process. This technology uses fluorinated amorphous carbon (a-C:F) with a dielectric constant of 2.3, sandwiched between layers of SiO2, which are formed in sequential by high density plasma-chemical vapor deposition (HDP-CVD) technique. Top SiO2 layer assures oxygen plasma resistance during via etching, metal etching, and resist removal.