ALIGNMENT MARK OF ELECTRON-BEAM EXPOSURE AND DETECTION METHOD OF ALIGNMENT MARK OF ELCTRON-BEAM EXPOSURE

摘要

PURPOSE:To shorten the detection time by a method wherein an alignment mark is detected in an electron-beam exposure operation and the number of scanning operations of an electron beam is reduced more than that in conventional cases when the mark is detected and to detect a position more precisely than in conventional cases even when the cross-sectional shape of a groove for the mark is asymmetrical. CONSTITUTION:An alignment mark 1 to which an arbitrary angle of rotation has been given in advance is arranged on a sample, both the X-axis and the Y-axis are scanned 2 only once by an electron beam in such a way that two parts in the side of the mark are traversed by one scanning operation, and the central position 4 of the alignment mark and the angle of rotation of the sample are found on the basis of the distance between two marks 3 which are obtained regarding them. In addition, a cross-shaped alignment mark which is composed of two parallel grooves is scanned by an electron beam, the correlation between signal components is operated on the basis of the two grooves, and the position detection accuracy of the alignment mark is increased. Even when the alignment mark is arranged so as to be turned on the sample, the number of scanning operations can be reduced to twice. Even when the cross-sectional shape of the grooves for the mark is asymmetrical, the position detection accuracy is not lowered.