METHOD TO MEASURE FEATURES WITH ASYMMETRICAL PROFILE

摘要

The present invention is directed to a method (58) for detecting asymmetry in the profile of a feature (82) formed on a wafer during the process of semiconductor fabrication. The method (58) encompasses directing a beam of light or radiation at a feature (66) and detecting a reflected beam associated therewith (68). Data associated with the reflected beam is correlated with data associated with known feature profile s(19) to ascertain profile characteristics associated with the feature of interest (192). Using the profile characteristics, an asymmetry of the feature is determined (192) which is then used to generate feedback or feedforward process control data (200) to compensate for or correct such asymmetry in subsequent processing.