| 摘要 |
PURPOSE:To detect thin foreign matter efficiently by detecting fluorescent light emitted by the foreign matter which absorbs irradiating ultraviolet rays and performing inspection by using a difference in coloring quantity with characteristics. CONSTITUTION:A reticle or mask as a body to be detected is placed on an XY stage 16, a mercury lamp 17 is turned on, and an ultraviolet ray with constant wavelength is passed through a filter 18 and reflected by a dichroic half- mirror 19 to irradiate the body to be detected. When there is no foreign matter on the body to be detected, the stage 16 is moved to another inspection position to irradiate the body to be detected, but when there is the foreign matter, light with different wavelength from the illumination light is emitted by the foreign matter. This light passes through the half-mirror 19 and is detected and measured by a sensor 20. Then its output is compared by a comparator 21 with previously inputted data to generate a warning when they are different and decides the presence of the foreign matter when they are equal. |
