Full Wafer Stress Metrology for Dielectric Film Characterization: Use Case

Abstract

With the introduction of new materials in Back-End of Lines to overcome the development of new options in mature technologies, controlling the local stress and establishing its potential impact on yield becomes more and more critical. In the same way, for high volume production control, it is also important to verify that process equipments of the same kind actually deliver the same materials characteristics as well as to identify which hardware parameters of the process equipment itself can influence the resulting film properties. In this context, this paper will demonstrate how metrology techniques can provide relevant and rapid information on the stress characteristic at the deposition process step itself. This will be illustrated by exploring the impact of wafer centering in a Chemical Vapor Deposition (CVD) dielectric deposition chamber for the case of final Nitride passivation layer both on blanket and product wafers.