Integrated characterization of porous low-k films for identifying killer pores and micropores

The need of introducing higher density of nanopores into interlayer dielectrics to realize k<2.0 increases the danger of pore coagulation to form unexpectedly large 'killer' pores, which cause defects in Cu diffusion barrier layer to lead to device failure. On the other hand, unintentional small micropores with less than 0.7 nm in diameter are also problematic in terms of physico-chemical and mechanical stability. In this work, we employ two different low-k films with k=1.8 and show experimental results on the largeand small-ends of pore size distributions to address most important technological issues in ultra-low-k/Cu interconnects.