| 摘要 |
PURPOSE:To improve the precision of the state of superposition by forming checking patterns having the same shape to each of a plurality of photo-masks, superposing these patterns and deciding the precision of alignment. CONSTITUTION:The same checking patterns 12 are shaped severally to masks 11a-11c. The shapes of the images 13 of the checking patterns formed by using respective mask are decided, and the accuracy of superposition of these masks 11a-11c is inspected. The images 13 are inspected in such a manner that beams 10 shown in the arrow are projected and resist patterns are developed and measured. The shapes of the images 13 coincide with the shapes of the patterns 12 when all masks are relatively aligned correctly in the inspection method, but the shapes of the images 13 are made different from those of the patterns 12 when the masks are not relatively aligned precisely. Accordingly, the accuracy of the relative alignment of all masks can be decided by judging the shapes of the images 13. |
