| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To detect even a small defect with high throughput. <P>SOLUTION: An electron beam discharged from an electron gun 41 is irradiated onto a mask 44 to be checked via an irradiation lens 43 to form a crossover nearby a main surface of an objective lens 45. The electron beam passed through the mask 44 forms an optical image on a vacuum window 48 having a fluorescent surface inside thereof via the objective lens 45 and a magnifying lens 46 and the optical image is focused onto a TDI camera 50 to be converted into an electrical signal. Then the electrical signal is converted into a mask image at an image forming circuit 54, so that a defect is detected at a defect detecting circuit 55. An LaB<SB>6</SB>cathode of the electron gun 41 operates under conditions of space charge limitations to reduce shot noises and to obtain high brightness, and a magnifying lens system is set at S/N>20, thereby even the defect not more than a half of an image size may be detected. The defect not more than the half of the image size may be detected even if the MIF(E0) is set>0.55. <P>COPYRIGHT: (C)2004,JPO</p> |
