METHOD AND APPARATUS FOR CALIBRATING SUB-NANOMETER CRITICAL DIMENSION USING PITCH OFFSET

摘要

A method and an apparatus for calibrating sub-nanometer critical dimension using pitch offset are provided to reduce the pitch difference of a first pitch and a second pitch by comparing the first pitch with the second pitch. A method for calibrating sub-nanometer critical dimension using pitch offset comprises the steps of: measuring a first pitch; measuring a second pitch which is offset from the first pitch by a pitch offset value; comparing the first pitch with the second pitch; and determining the metrological accuracy of a metrology system from the comparison. The comparing step includes the pitch difference between the first pitch and the second pitch. The pitch offset value uses pitch offset which is below 1 nanometer.