| 摘要 |
PURPOSE:To enable a projection exposure unit to be produced at lower cost while improving the throughput, by performing the prealignment with the use of means for final alignment. CONSTITUTION:A wafer 34 is prealigned with respect to the external shape reference by a mechanical prealignment apparatus and then disposed and held on a stage 35 in a predetermined condition. The stage 35 is thereafter shifted in the x and y directions by predetermined distances so that a target mark 34c is moved to a position where it is to be scanned with sheet beams B1 and B2 means of an objective 24b and the beams are focused. Since the target mark 34c is a regular square with a side of about 1mm, the scanning area D of the sheet beams B1 and B2 can be positioned within the mark 34c even with mechanical prealignment precision of about 100-300mum. |
