Abstract: The scanning photon microscope according to this invention relates the phase of the ac photovoltage or photocurrent signal to the hue of a color image and the amplitude of the signal to the brightness of the image in representing the signal distribution in the specimen in the form of a color image, in order to make a clear distinction between the amplitude and phase of the ac photovoltage or photocurrent induced in the specimen when irradiated with a photon beam, thus permitting detailed and multilateral analysis of the specimen's characteristics.

Abstract: A pattern defect inspection apparatus detects presence or absence of a defect in a pattern formed on a semiconductor wafer by scanning the pattern normally to the surface thereof by a coherent light beam of a predetermined spot size, detecting reflected diffraction lights generated thereby and processing the detected lights. It comprises an abnormal direction signal detector including photo-detectors having wide light receiving areas arranged in a plurality of spatial areas which the reflected diffraction lights from a normal pattern do not normally reach, a normal pattern detector including photo-detectors having large light receiving areas arranged in a plurality of spatial areas which the reflected diffraction lights from the normal pattern reach, and a defect discriminator for determining if the abnormal direction signals are due to a true defect or not in accordance with the signals from the abnormal direction signal detector and the normal pattern detector.

Abstract: The present invention relates to viewing a three-dimensional internal structure of a specimen. According to the invention, it is possible to observe the internal structure of a particular cross section of a specimen as clearly differentiated from the other cross sections. The characteristic features of the invention lie in that a plurality of light beams passing through different portions inside the specimen are used, and a correlation among the measurements of transmittance of the plurality of light beams is determined.