Dielectric Reliability of 50 nm Half Pitch Structures in Aurora^{\textregistered}LK

The dielectric reliability of Aurora (R) LK (kappa = 3.0) material has been evaluated on a 50 nm half pitch test structure. These were fabricated using a double patterning scheme and TiN metal hard mask. The introduction of a suitable post-etch residue removal step and close-coupled processing between Cu electroplating and chemical mechanical polishing were found to be key for achieving high yield. Median time-dependent dielectric lifetime of 10 years is reached at an electrical field of 1.4 MV/cm, comparable to earlier reported results with SiO(2) as dielectric. The reliability performance is found to be significantly layout dependent with corners being weak points due to local field enhancement. (C) 2009 The Japan Society of Applied Physics