ALIGNMENT MEASURING METHOD OF PHOTOLITHOGRAPHY PROCESS

摘要

PURPOSE: A method for measuring the alignment in photography process is provided, to allow the error range to the expansion and contraction of transcribed pattern image to be calibrated more effectively and reliably. CONSTITUTION: The method comprises the steps of removing an asymmetric part by metal deposition and measuring the overlay to each short region; and measuring the extent of expansion and contraction to each short region of edge based on the short of central region of a wafer to calibrate the overlayer measurement value. The step for removing an asymmetric part by metal deposition and measuring the overlay to each short region is performed by substituting the ratio of expansion and contraction according to the pattern stepped difference of each short region containing an align mark and the thickness of deposited metal foil; and the step for measuring the extent of expansion and contraction to each short region of edge is performed by obtaining the extent of expansion and contraction to each short region of edge of similar condition by substitution of the calibrated value to the ratio of expansion and contraction to the short of central region of a wafer and re-determining the overlayer measurement value to the ratio of expansion and contraction to the total region of a wafer.