| 摘要 |
PURPOSE: To obtain enact exposure in the minimum number of shots by allowing a pulsed light source to have variable attenuating amounts in a controllable form. CONSTITUTION: A pulsed source 10 is normally a pulsed laser, and the pulsed light passes through a variable attenuator 20 which controllably attenuates a light pulse before an exposed device is irradiated. One part of the light pulse is measured by an exposure monitor 30 for deciding the influence, and a controller 50 connected with the variable attenuator 20 and the pulsed light source 10 decides the minimum attenuating amounts necessary for executing desired exposure by using information from the exposure monitor 30. Thus, the exact exposure can be obtained in the minimum number of shots. |
