Challenges of chip-to-package interaction for 22nm technology with ultra low k and Pb-free interconnects

A review of the chip-to-package interaction (CPI) results during the development and qualification of IBM´s 22SOI high performance technology will be presented. Initial results and failure modes using ultra low-k (ULK) dielectric BEOL during the early development phase are shown. The fail modes include BEOL cracking under solder pads due to ULK formulations, from both planned material formulations and material properties related to tool excursion events, and leakage failures under high temperature, bias, and moisture attributed to incomplete formation of die edge seal. Full qualification data on a final robust process showing excellent CPI performance for this technology node are presented.