Defect Reduction by Nitrogen Purge of Wafer Carriers

Abstract

Nitrogen purge of wafer carriers is driving defect density reduction at critical process steps. We discuss several examples of defect creation related to the environment of the semiconductor wafer and how nitrogen purge of carriers improves defect density. We have applied nitrogen purge at the gate formation, SiGe epitaxy and silicide formation process steps and we report experimental split data from in line inspection and the result at electrical test. From the impact of the nitrogen purge we can draw conclusions about the nature of defect formation. The impact on volume manufacturing is demonstrated.