Abstract: A plate thickness measuring method and apparatus, is provided wherein a fine pattern is projected on the front and rear surfaces of an object to be measured via object lenses oppositely provided on the front and rear surfaces of the object to be measured in its thickness. The image of the projected pattern on the object to be measured is formed via said object lenses, and the contrast of the formed pattern image is detected. Then the object lenses are moved slightly to achieve the maximum of the contrast, or to perform an automatic focusing control. The thickness of the object to be measured can then be estimated from the difference of the positions of the object lenses at which the maximum contrast, or the focused condition, are obtained.

Abstract: A pattern detection system for inspecting defects in fine or minute patterns such as photomask patterns at a fast speed is disclosed. The system comprises an illuminator, a device for moving objects with the patterns to be inspected with being illuminated by the illuminator, an optical system for imaging the objects, a scanner for scanning the objects in a direction intersected at a given angle with respect to direction of the objects moved by the moving device and arrays of photosensors arranged linearly in a direction perpendicular to that of images on the objects scanned by the scanner, on the surface of which the images are formed by the optical system and for producing respective outputs parallelly on the time basis.

Abstract: An exterior view examination apparatus comprising a movable sample stage provided in a sample chamber of a scanning type electron microscope; a sample mounted on the stage; and an optical microscope which can observe the sample from an exterior of the chamber, mounted on the chamber in parallel with the scanning type electron microscope, the position of a surface part of the sample (mounted on the sample stage) to be observed, measured or analyzed being preliminary defined by the optical microscope, and the sample stage being moved by a certain amount thereby to bring the sample at the center of the visual field of the electron microscope.

Abstract: The nuclear resonance signal obtained from the sample is stored in a memory circuit and the stored signal is then repeatedly read out. A periodic function which is derived as a result of the transformation of a triangular wave into a trapezoidal one, is used for the Fourier transformation of the repeatedly read-out signal. The adverse influence of the transient phenomenon in the h-f impulse signal on the resultant spectrum is eliminated by stopping the Fourier transformation only during the initial portion of the read-out period of the memory circuit.