Variation

Variation afflicts the design, manufacture, and operation of integrated circuits. Techniques and tools are needed in three areas to address variation: statistical metrology, advanced process control, and design for manufacturability. First, statistical metrology seeks to characterize and model variations and their sources. Advanced metrology helps to understand geometric and material property variations, while variation test structures and test circuits enable study of the impact of specific or aggregate variations on performance. Second, advanced process control attempts to reduce process variation through sensing and feedback/feedforward control during fabrication. Third, design for manufacturability (DFM) seeks methods to improve performance and yield given process and environmental variation, through robust design, increased regularity, and other approaches. Finally, linkages between these areas, particularly between statistical metrology and DFM, will be important and empowering.