| 摘要 |
<p>PROBLEM TO BE SOLVED: To perform alignment without using a specific alignment mark. SOLUTION: In an alignment method used for multi-exposing a reticle pattern on a wafer, a part of a lower layer pattern formed on the wafer is extracted as a wafer side alignment mark and is previously registered in an image recognition equipment. At the time of aligning, a shift error is calculated by collating and superimposing an actual mark Ma, i.e., an extraction target of lower layer pattern, and the registered mark M, so as to calculate a shift error, and based on the calculated value, the water is aligned with the reference position. The versatility of a stepper and reduction projection alignment can be improved, degree of freedom in selecting a wafer side mark can be increased and a combined use of a step-and-repeat alignment, step-and-scan alignment, electron beam direct lithography, etc., can be promoted, by eliminating the arrangement of a specific alignment mark.</p> |
