Abstract
This paper presents the problems, the solutions, and the development state of the novel 0.18 μm Cu Metal Process through failure analysis of the Alpha CPU under development at Samsung Electronics. The presented problems include : “Via Bottom Lifting” induced by the Cu Via void, “Via Bottom dissociation” due to the IMD stress, “Via side dissociation” due to the poor formation of the Barrier Metal, “Via short/not-open failure” due to the IMD lifting, and Cu metal Corrosion/Loss. The analysis was carried out on the Via Contact Test Chain Patterns, using the “Electron (ION) Charge Up” method. After carefully analyzing each of the failure types, process improvement efforts followed. As a result, the pass rate of the via contact Rc was brought up from a mere 20% to 95%, and the device speed higher than 1.1 GHz was achieved, which surpasses the target speed of 1 GHz.
