Spectroscopic CD technology for gate process control

Spectroscopic CD (SCD) technology provides high precision shape information with excellent correlation to established critical dimension metrology. Poly-gate wafers from over 20 lots produced in a high-volume manufacturing fab were measured and analyzed with KLA-Tencor's SCD and SEM CD tools. APC simulations on the SCD data demonstrate the potential to reduce the CD deviation from the process target. Focus-exposure process window analysis using additional shape information available with SCD shows the potential value of the more complete view for lithographic cluster tool monitoring.