Suppression of galvanic corrosion in advanced BEOL integration

摘要

The data presented confirms the ability of the single wafer closed chamber system to reduce and effectively control oxygen levels. This was accomplished without the addition of corrosion inhibitors or oxygen scavengers. Applying this approach to the more sensitive system where copper and CoWP SAB are exposed and susceptible to galvanic corrosion has proven successful as well. As part of a 32nm BEOL development program, this system has been successful in eliminating CoWP corrosion across the entire wafer surface; corrosion that would otherwise be present without the complete control of oxygen in the processing fluids and chamber environment.