| 摘要 |
PURPOSE:To provide a high-performance scanning electronic microscope which is equipped with a secondary electron detection system capable of trapping secondary electrons with high efficiency from low acceleration voltage to high acceleration voltage, and which is small in terms of the deflection quantity of primary electrons and astigmatism. CONSTITUTION:When a primary electron beam 1 is radiated onto a specimen 3, secondary electrons 2 emitted therefrom move upwards while making spiral motions. After having been moved away from an objective lens, the secondary electrons diverge quickly as a result of a decrease in the magnetic flux density and are deflected by a drawing field from a secondary electron detector 4, and thus are trapped in the same. In order to prevent the primary electron beam 1 from being exposed to the drawing field from the secondary electron detector 4 and thereby deflected, a shield electrode 8 is provided which has an opening permitting transmission of the secondary electron 2 therethrough, by which the secondary electron 2 is not obstructed by the shield electrode 8 and is trapped into the secondary electron detector 4. This enables large reduction in the deflection quantity and astigmatism of the primary electron beam so that deterioration in yield of the secondary electron is prevented. As a result, it is possible to realize a high-performance scanning electronic microscope with high resolution and high sensitivity. |
