| 摘要 |
<p>PURPOSE:To make an inspection efficient by dividing a photomask area into fields, comparing a measured value of a black to white ratio for patterns present in the field with a value calculated from inspection data, and making the inspection by collating the field pattern with a pattern generated from the inspection data only when the measured value and the value calculated from the inspection data do not coincide with each other. CONSTITUTION:A photomask 10 comprises a pattern consisting of a transparent part and a photoabsorptive part. An area over the photomask 10 is divided into small areas 11, 12, and so on. An inspection device 7 measures a black to white ratio (B:W) sequentially for each of the small areas 11, 12, 13, and so on. Such a value is obtained from both light beam scannings by a light source 31 and intensity values of a transmitted light detected by a light receiving part 32. Upon every measurement of the B:W ratio for each of the small areas 11, 12, and so on, such ratio is compared with a B:W ratio of the corresponding fields of the inspection data 20. Only when the measured B:W ratio does not coincide with that stored in a memory, such non-coincidence is indicated on a display of an output system 35. According to the constitution, the time required for inspecting photomasks by comparison can be shortened, thereby reducing the inspection cost.</p> |
