| 摘要 |
PROBLEM TO BE SOLVED: To detect a defect such as foreign matter or deposit on the surface of an inspection object and an internal hollow defect, distinctively with high resolution. SOLUTION: A laser emitted from a laser device 5 is polarized through an analyzer 6 and allowed to enter the inspection object W from an oblique direction, and scattered light SB is imaged by a CCD camera installed on a dark field through an analyzer 8 arranged in a cross Nicol state, and the intensity of the scattered light is determined from acquired image data. The inspection object can be switched into the state where an ultrasonic wave is not applied or into the state where the ultrasonic wave is applied. The scattered light is detected and its intensity is determined in the state where the ultrasonic wave is not applied to the inspection object and in the state where the ultrasonic wave is applied thereto, respectively. It is determined that, when the difference between both intensities of the scattered light exceeds a prescribed threshold, the scattered light is generated from a hollow defect in the inspection object, and that when the difference does not exceeds the threshold, the defect belongs to another kind. COPYRIGHT: (C)2008,JPO&INPIT
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