| 摘要 |
PURPOSE:To improve the exposing area setting accuracy of an exposing device by detecting the positional relation between light shielding means which limit the exposing area and the circuit pattern section of a mask. CONSTITUTION:A total of four positional deviation detecting means 6 are provided for detecting positional deviations between alignment marks 101 on a mask 1 on the periphery of a circuit pattern 102 on the mask 1 and alignment marks on a water 2. Aperture blades 4 are sufficiently retreated from the marks 101 so that they cannot intercept the laser beams 601 of the means 6 reaching the marks 101. When the blades 4 comes to positions where they cover the marks 101 against the beams 601, drive controlling sections of aperture stages 401 receive signals from signal processing sections of the means 6 and obtain the positional information of the marks 101 of the blades 4. When the marks 101 are not exposed against the laser beams 601, the blades 4 are retreated by prescribed amounts upon detecting the positional deviation between the wafer 2 and mask 1 and, when the marks 101 are exposed, the blades 4 are advanced. When the blades 4 are repeatedly retreated and advanced in such way, the exposing area setting accuracy can be improved. |
