| 摘要 |
PROBLEM TO BE SOLVED: To provide a scanning electron microscope, capable of detecting secondarily generated electrons from a sample with high detection efficiency by using a semi-in-lens type object lens. SOLUTION: In this scanning electron microscope, the acceleration voltage of an electron beam EB irradiated on a sample 2 is set to 4 kV, and a voltage of -3 kV is applied to the sample 2 from a power source 11, so that the electron beam EB is decelerated immediately in front of the sample and is irradiated on the sample 2 with an energy of 1 kV. Secondarily generated electrons 14, such as secondary electrons generated by the irradiation of the electron beam on the sample 2, are bound by a lens magnetic field and advances upward in spiral form. The energy of the secondary electrons 14 at that time is always set to a value of the application voltage to the sample 2 or higher. The secondary electrons 14 which have ascended linearly move from a position, where the magnetic field of an object lens 1 becomes weak, collide with a first reflecting cylinder 12 or a second reflecting cylinder 13 and generates a large quantity of secondary electrons 15 from the reflecting cylinders 12, 13. In the vicinity of an opening 9 of an inner magnetic pole 6, an electric field based on a voltage applied to the front face of a detector 10 is formed. The secondary electrons 15 generated from the reflecting cylinders 12, 13 are directed toward the detector 10 by the electric field and detected.
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