| 摘要 |
PROBLEM TO BE SOLVED: To reduce influence of space charge and generation of deflection aberration by reducing optical path length of an electron optical system. SOLUTION: An electron beam emitted from an electron gun 1 forms a reduced image on a sample 18 through a multi-opening 2, a reducing glass 3, a non-dispersing Wien filter 5, a tablet lens 10, an electromagnetic deflector 11, a beam separator 12 and a tablet lens 17 constituting an objective lens. Since the beam separator 12 is constituted so that the passage distance of a secondary electron beam within the beam separator 12 becomes about 3 times the passage distance of a first electron beam within the beam separator 12, the secondary electron beam can be deflected about 30 degrees or more even if a magnetic field in the beam separator 12 is set to deflect the first electron beam only by a small angle of about 10 degrees or less, thus, the first and secondary electron beams are sufficiently separated. Since the first electron beam is deflected only by a small angle, aberration caused in the first electron beam is small. COPYRIGHT: (C)2007,JPO&INPIT
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