| 摘要 |
PURPOSE:To output an appreciation signal to appreciate the extent of astigmation compensation without including the error by adding a modulation signal generating circuit which is to micro-scan an electron beam with samller width than that of the horizontal scanning and with higher frequency than that of the horizontal scanning. CONSTITUTION:A micro-scanning circuit 14 is provided on an electron beam device such as a scanning electron microscope, sine and cosine value of rotational angle in the scanning direction determined with a setting circuit 17 are multiplied by a saw-tooth wave from the oscillator 15 with multiplicators 16X, 16Y to output, and the output together with signals of a horizontal scanning circuit 10X and vertical scanning circuit 10Y is supplied to adders 11X, 11Y to control horizontal and vertical scanning coil 9X, 9Y through a multiplying controlling circuit 18. A secondary electron signal from a detector 19 is operated with a circuit 22 through a differentiation circuit 20 and an integrating circuit 21 to display. Thus the scanning area becomes same regardless of the rotation of the scanning direction to extrude the error, and an improved appreciation signal can be obtained. |
