| 摘要 |
PROBLEM TO BE SOLVED: To provide an image of high resolution compared with the case that visible light is used as illumination light by projecting high-brightness ultraviolet light(UV light) which is emitted from a laser light source on a sample while reducing its coherence. SOLUTION: While a semiconductor wafer 1 which is an example of a pattern to be inspected is moved at a constant speed when scanning a stage 2, the brightness information of a pattern to be inspected which is formed on the wafer 1 is detected with an image sensor 8. A gradation recognition converter 10 performs logarithmic conversion and exponential/polynominal conversion, etc., and an image wherein illumination light causes thin-film interference for unevenness in brightness is corrected with a thin film formed on the wafer in process. A discharge lamp is excellent as an UV(ultraviolet) light source, with, especially related to a mercury xenon lamp, the bright line in UV region stronger than other discharge lamps. By inserting a diffusion plate on the optical path of an UV laser for rotation and reciprocation, the spatial and time-related coherence is reduced simultaneously. Since a short-wavelength UV or a DUV laser is used with its coherence reduce, the defect of circuit pattern is detected with high precision.
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