| 摘要 |
<p>PROBLEM TO BE SOLVED: To realize a rough-vacuum scanning electron microscope which can effectively detect secondary electrons even at a low degree of vacuum. SOLUTION: Secondary electrons from a sample 25 is given a rotational movement by magnetic field M of a semi-in-lens type objective lens 23, and gathered on an optical axis line. The secondary electrons gathered on the optical axis line are guided upward by electric field E1 of an accelerating electrode 43. Therefore, the secondary electrons generated from the sample 25, gathered effectively, are guided to the top part of an orifice 29 through an opening of the orifice. The secondary electrons entering the objective lens are prevented by an electric field E2 formed by a decelerating electrode 44 from proceeding to the top part of the objective lens. The secondary electrons inside the objective lens is drawn toward a secondary electron detector 35 by an electric field E3 formed by its corona ring 36, and accelerated, to collide with a scintillator 37 of the secondary electron detector 35.</p> |
