Method and apparatus for alignment.

摘要

A method an apparatus for alignment used in X-ray exposure or the like, wherein the operation comprises the steps of:
preparing a mask (3) which has a symmetrical formation of an alignment pattern (7) made up of a plura­lity of linear segments formed in a peripheral section of said mask (3), and a wafer (1) which has a formation of an alignment pattern (19) formed in a same direction as of the alignment pattern of said mask and made up of linear segments;
illuminating said mask alignment pattern (19) along a direction inclined to said alignment direction using an illumination means;
imaging said mask alignment pattern (19) and said wafer alignment pattern (18) using an imaging means and transforming the image into a video signal;
converting the video signal into a digital signal using an A/D conversion circuit (33) and storing the digital signal in a memory (34);
reading out the digital video signal from said memory, and averaging the digital video signal in a mask alignment pattern area by removing a shadow portion (51) caused by said mask alignment pattern (19), and further averaging the digital video signal in a wafer alignment pattern area;
detecting a relative displacement between the mask (3) and wafer (1) from the averaged mask alignment pattern signal detected and averaged wafer alignment pattern signal detected; and
aligning the mask (3) and wafer (1) by moving one of the mask and wafer so that the displacement between both members does not exist.