| 摘要 |
PURPOSE:To enable to automatically detect a foreign substance only existing at the transmitting region of the exposure mask and pattern by a method wherein a laser beam is irradiated vertically to the exposure mask, the laser beam is made to transmit and the scattered light of the transmitting light, which is generated due to such the foreign substance as dust, is detected. CONSTITUTION:A laser beam 4 is irradiated on a foreign substance 3 existing at a part of an exposure marsk 1, where exists no light-shielding pattern 2, the laser beam 4 is turned into a scattered light 5, is led to a photomultiplier 7 through plural pieces of optical fibers 6 being disposed toward the point of intersection of the laser beam 4 and the surface to be inspected of the exposure mask 1, is converted into an electric signal, and the foreign substance 3 is detected, while the laser beam 4 is not irradiated on foreign substances exisiting at the parts of the light-shielding patterns 2 of the exposure mask 1, because the beam 4 is intercepted by the light- shilding patterns 2, and the substances are not detected. Accordingly, it becomes possible to detect the foreign substance only at the transmitting region of the exposure mask on the exposure mask, which can become a defect in the exposure transferred image. By combining this detecting method with a reduced projection type exposing device, the quality of the image of the exposure mask, which is formed on the photo resist coating, can be improved. |
