| 摘要 |
PROBLEM TO BE SOLVED: To realize a scanning charged particle beam device to enlarge the range of electromagnetic visual field movement by correcting oblique aberration and to eliminate the need for turning off the electromagnetic visual field movement even when maximum resolution is obtained. SOLUTION: A computing unit 18 receives a set of numerical values (nx , ny ) proportional to an electromagnetic visual field movement distance (Xi , Yi ) from an up/down counter 17. Further, it receives bias data such as alignment data, axial astigmatic data and focus data from an optical system control device 19 to generate D/A conversion data for eight poles astigmatic correction device 9, electromagnetic visual field movement deflecting devices 3 and 5, and an objective lens 7. Since a current supplied to the astigmatic correction device 9 includes a correction component of axial astigmatism caused by asymmetry of the objective lens 7, a spot is truly circular when Xi =Yi =0. An oblique astigmatic correction current is generated to correct oblique aberration when Xi≠Yi≠0.
|
