Holistic approach using accuracy of diffraction-based integrated metrology to improve on-product performance, reduce cycle time and cost at litho

摘要

High-end semiconductor lithography requirements for CD, focus and overlay control drive the need for diffraction-based metrology and integrated metrology. In the advanced nodes, more complex lithography techniques (such as multiple patterning), use of multi-layer overlay measurements in process control, advanced device designs (such as advanced FinFET), as well as advanced materials (like hardmasks) are introduced. These pose new challenges for litho-metro cycle time, cost, process control and metrology accuracy. In this publication a holistic approach is taken to face these challenges via a novel target design, a brand new implementation of multi-layer overlay measurement capability in diffraction-based mode and integrated metrology.