| 摘要 |
PURPOSE:To make it possible to measure a minute probe diameter, so far not possible to measure, by measuring plurally the probe diameter at the points extended from the smallest probe. CONSTITUTION:By placing a probe diameter measuring device variable in the optical axis (height) direction, and the probe diameter at a specific sampling position is computed from plural measurements. First, a sample board 14 is moved to the position where the tip of a knife edge 16 is at the electron beam radiating position, through a controller 25 and a sample board control unit 23. Then, the electron beams 11 are scanned to intersect the knife edge 16, the transmitting beam current is synchronized to a deflecting signal fed by a Faraday cup 18 to a deflector 15, and the value is detected. The detected signal is input to the Y of an XY recorder 24 through a signal multiplier 21 and a differential unit 22, while the deflecting signal is input to the X. The lateral axis of the recorder output indicates the scanning position and the vertical axis shows the differential signal intensity. The distance between two intersecting points of a straight line 1/e of the differential signal intensity and a differential signal wave is measured as the probe diameter d to be found.
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