| 摘要 |
PURPOSE:To correctly monitor a beam position on a sample by forming a charged particle detector, which detects secondary electrons and secondary ions being emitted from the sample, of a dougnut-shaped channel plate having the opening part in the center. CONSTITUTION:Ions from an ion source 12 are made to pass through a diaphragm 13 for being focused on a sample 4 by means of an electrostatic lens 14 in order to scan by deflectors 15 and 15'. Then, the secondary electrons 2 and the secondary ions 3 from the sample 4 are detected by a dougnut-shaped channel plate 16 having the opening part is the center for being put in a CRT21 through an amplifier 23 in order to perform observation of a scanning ion microscopic image. Accordingly, by using the channel plate 16 the average detection direction of the secondary electrons and the secondary ions 3 accords with the irradiation direction of an ion beam without being shaded from the detection direction regardless of roughness of the sample 4 thus being able to correctly monitor an irradiation beam position of the sample 4. |
