Metrology control for an advanced 200 mm sub-micron wafer fab

The advent of sub-micron technology in semiconductor device fabrication has placed a greater emphasis on calibration control of metrology instruments. As device dimensions shrink, accuracy requirements for such instruments is gaining more importance. This paper will discuss the initial set-up methodology during start-up and the control procedures for routine maintenance of metrology instruments in our advanced sub-micron wafer fab. A methodical approach to determining systematic error associated with metrology instruments, using the concepts of tool accuracy, gauge repeatability and reproducibility is presented. Start-up and routine monitoring results for certain metrology instruments such as ellipsometers, scanning electron microscopes, and particle detectors is presented to illustrate our approach.