Secondary electron filtering method, defect detection method and device manufacturing method using the same method

摘要

If a conventional mesh filter is used for a voltage contrast measurement on a specimen surface, aberrations that is difficult to correct in a primary electron (PE) beam are generated and then it is difficult to obtain a fine focused beam. An axially symmetric electrode is placed between the secondary electron (SE) detector and the specimen. Through an adjustment for an applied voltage in the electrode, a potential on the optical axis above the specimen is adjusted so that a passage or non-passage of the SEs can be controlled.