| Popis: |
Alternating phase shift reticles are one proposed solution for printing features required at the 90 nm and 65 nm nodes using 193 nm lithography. A key enabler to the adoption of this technology is defect inspection so as to guarantee defect free reticles are delivered to wafer fab production. A test reticle with programmed sub-180 degree phase bump and divot defects has been developed that is representative of the sub-90 nm node. This reticle is characterized by SEM methods. This test reticle in turn is used to determine the defect detection performance of a DUV reticle inspection tool, which uses a phase contrast enhanced optical system to improve the detection of phase defects. This presentation discusses several of the challenges in the design and manufacture of the programmed defect test reticle, the reticle characterization results, and the inspection station results. Defect review methods are described which differentiate between chrome, phase bump, and phase divot defects. Additionally, a best known methodology (BKM) is discussed for the manufacture of alternating phase shift masks based upon detecting killer defects before significant additional value is added. |
