Patent 7679055 was granted and assigned to Hitachi on March, 2010 by the United States Patent and Trademark Office.
An evaluation method and apparatus is provided for evaluating a displacement between patterns of a pattern image by using design data representative of a plurality of patterns superimposed ideally. A first distance is measured for an upper layer pattern between a line segment of the design data and an edge of the charged particle radiation image, a second distance is measured for a lower layer pattern between a line segment of the design data and an edge of the charged particle radiation image; and an superimposition displacement is detected between the upper layer pattern and lower layer pattern in accordance with the first distance and second distance.