| 摘要 |
PURPOSE:To inspect a pattern formed onto a dummy substrate by scanning the upper section of the substrate, to which the pattern is shaped, by two rays and detecting the difference of beams transmitting the substrate. CONSTITUTION:The same pattern sections of two adjacent elements among the patterns formed to the surface of the dummy substrate 11 are each scanned simultaneously by two minute spotty rays projected from a light source 13. Beams transmitting the substrate 11 are each received by means of photomultipliers 15, 15', converted into electrical signals corresponding to the intensity of transmitted light, amplified by means of picture amplifiers 16, 16' and transmitted to a differential amplifier 17. When the pattern of one element has a defect, two input of the amplifier 17 do not agree. A CPU 14 detects the defect by the output value of the amplifier 17, and transmits a signal indicating the defect to a printer 18 and a video monitor 19. |
