| 摘要 |
PURPOSE:To enable transfer of the pattern of a reticle to a photosensitive body in the state in which the magnification change rate of a projecting optical system attains a specified value by controlling the exposing energy incident on the projecting optical systen in unit time thereby maintaining the specified energy. CONSTITUTION:A shutter driving part 67 opens and closes a rotary shutter via a motor. A CPU60 calculates the adequate exposure for exposing adequately photoresist according to the sensitivity of the photoresist coated on a wafer 11 and feeds the same to a shutter driving part 67. The sensitivity of the photoresist is fed from a keyboard 69 via an interface 61 to the CPU60. The CPU60 calculates the shutter opening time for maintaining the specified exposing wavelength energy to be made incident on a projecting lens and feeds the calculated time to the part 67. The rotary shutter is intermittently rotated by a motor according to the calculated time and therefore the incident energy to the projecting lens is made constant and the magnification change rate thereof is maintained constant. |
