CROSS-SECTIONAL SHAPE DETECTOR FOR OPENING

摘要

PURPOSE:To detect the quality of a sectional shape of an object to be tested by comparing the amptitude, strength and the like thereof for elements of specified order separately detecting Fourier spectrums of lights when they are irradiated on the object having a number of openings in the vertical direction and a specified inclined direction. CONSTITUTION:Beams emitted from a laser 14 are irradiated on an object to be test 11 comprising a substrate 12 having a number of openings 13 with an angle theta of the cross-sectional inclination in the vertical direction and a direction inclined by an angle theta and the transmitted beams are received by a spectrum detection system 16 via a lens 15 to obtain Fourier spectrums of the beams separately. Both spectrums are compared on the amplitude, strength and the like for elements of specified order to determine abnormality of the sectional shape depending on the resultant difference. This enables the detection of the quality of the sectional shape simply and accurately.