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Image Noise Reduction Using Structural Mode Shaping for Scanning Electron Microscopy  

Hamochi, Mitsuru (JEOL Ltd)
Wakui, Shinji (Tokyo University of Agriculture and Technology)
Publication Information
International Journal of Precision Engineering and Manufacturing / v.9, no.2, 2008 , pp. 28-33 More about this Journal
Abstract
In a scanning electron microscope (SEM), outside acoustic noise causes image noise that distorts observations of the specimen being examined. A SEM that is less sensitive to acoustic noise is highly desirable. This paper investigates the image noise problem by addressing the mode shapes of the base plate and the transmission path of the acoustic noise and vibration. By arranging the position of the rib, a new SEM base plate was developed that had twisting as the 1st and 2nd modes. In those two twisting modes, vibration nodes existed near the center of the base plate where the specimen chamber is placed. Less vibration was transmitted to the chamber and to the specimen by the twisting modes compared to bending ones, which are the 2nd and 3rd modes for a rectangular plain base plate. An SEM with the developed base plate installed exhibited a significant reduction of image noise when exposed to acoustic noises below 250 Hz.
Keywords
Scanning electron microscopy; Mode shape; Natural frequency; Acoustic noise; Resonance;
Citations & Related Records
Times Cited By KSCI : 3  (Citation Analysis)
Times Cited By Web Of Science : 3  (Related Records In Web of Science)
Times Cited By SCOPUS : 2
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