Patent ID: 6563116
Filing Date: 2003-05-13
Classification: G01B,H01J

Abstract:
A method of measuring sizes of trapezoidal objects along their lower base, comprising the steps of positioning an object to be measured in a scanning electron microscope so that a line of scanning of an object by an electronic beam corresponds to a direction along which a measurement is performed; selecting a magnification of the microscope so that an image of the object to be measured occupies a substantial part of a length of a scanning line; scanning a video signal of the object in accordance with coordinates along the scanning line; analyzing a shape of the video signal to determine whether the object to be measured has a smaller base facing upwardly so that the object forms a trapezoidal projection or downwardly so that the object forms a trapezoidal groove; determining a location of stepped slopes on edge maxima of the video signal; determining on each stepped slope of each edge maximum a reference point as a point on a lower step of the stepped slope where an absolute value of a derivative of the video signal has a maximum value, and fixing of abcissa of said reference points in pixels, and calculating a size of the trapezoidal object along its lower base in pixels as the difference of the abcissas of reference points at two edge maxima.