Alignment device

摘要

An alignment device of a type, wherein an alignment pattern provided on a mask for fabrication of a semiconductor circuit element and an alignment pattern provided on a wafer are photoelectrically read in a dark field by a flying spot scanning system or a flying image scanning system to detect a relative positional relationship between the mask and the wafer, and a desired positional relationship is obtained by moving at least one of the mask and wafer on the basis of a detected signal. The novel feature of this alignment device resides in that the size of a line forming the alignment pattern along the scanning line is twice or more as large as the size of the scanning spot.