| 摘要 |
PURPOSE:To obtain an electron microscope device in which the contraction rate of a beam can be increased, the beam diameter can be made small while maintaining beam current high and any curve or distortion of the beam can be prevented. CONSTITUTION:A pair of secondary-electron detectors 10a and 10b are installed symmetrical relative to the center axis of a mirror body 1a. A cylindrical secondary-electron decelerating electrode (called a secondary electrode hereafter) 29 is used and installed inside an objective lens 7. The above pair of detectors 10a and 10b are positioned above the secondary electrode 29 and the objective lens 7, and detect secondary electrons B2 deflected and decelerated with the secondary electrode 29, the secondary electrons B2 then being applied to a common video amplifier. Owing to such a constitution, alphas can be made large by decreasing working distance, thereby enabling the beam diameter to be made small while maintaining the beam current at a high level. Besides, there is no possibility that a beam (B1) is curved or distorted by secondary-electron-drawing voltage applied to the detectors 10a and 10b. |
