| 摘要 |
PURPOSE:To correct the rotation of an image rapidly and easily by correcting the scanning direction of the electron beam of an electron microscope according to the rotational angle of a measured object. CONSTITUTION:The neighborhood of a positioning reference 10 is illuminated by a light source 13 and the inclination angle of an orientation flat 21 to the positioning reference 10 is detected by a pair of one-dimensional image sensors 14a, 14b mounted on the both end parts of said positioning reference 10. An angle computing unit 16 feeds out a correction signal correcting the deflection of an electron beam 2 to a deflection controlling part 17 on the basis of the detected values. Deflecting current waveform 25 in Y-direction varies uniformly during one period Ty of Y-direction scanning as shown by broken line in the case with no correction, but in the case with correction by correction signal varies staircasewisely corresponding to one period Tx of X-direction and corrects the scanning direction of the electron beam, thereby correcting the rotation of a pattern image 20 on a screen 19 caused by the rotation of a semiconductor wafer W by an angle theta so that the pattern image may be in parallel state to X-axis and Y-axis.
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