SPIE - Education Metrology of Image Placement SC1158

This course explains basic principles of metrology of image placement for applications to registration, alignment, and overlay in IC manufacture. Starting with IC Design Rules, and device pattern size and placement as their basis, this course outlines a systematic approach to dimensional metrology. Device pattern variation in mask-making, lithography imaging, image recoding, and image transfer, and down-stream wafer processing, are discussed leading to requirements of dimension metrology and control. Expectations in metrology of image placement are examined in the context of semiconductor design and manufacturing paradigm: device invariance in transformations of symmetry and translation, universal coordinate system, and absolute scale being the foundation of IC design. The same attributes built into IC design are maintained in production by the use of isoplanatic lithography systems, dimensionally stable masks, stages, and wafers, control of long distance scale and, of course, spatially uniform semiconductor processing. The key performance metrics for metrology of image placement are defined and illustrated in applications to improving robustness and accuracy in production environment. Systematic quantitative validation of those expectations for metrology systems and targets being measured, with complementary validation means and measurement technology, lay the foundation for certifiably accurate metrology of image placement and comprehensive control of overlay in IC manufacture.