| 摘要 |
<p>PURPOSE: To restrain the expansion angle of an electron beam without greatly decreasing an emission current value for a field emission type electron gun which has an emitter group as an emission current source formed by a plural of emitters. CONSTITUTION: A field emission type electron gun has a gate electrode 5 formed on a silicon substrate 1 with sharp emitters via oxide films 3, 4 and a focusing electrode 7 formed thereon via an oxide film 6. For setting the potential of the focusing electrode of the field emission type electron gun, an electron beam from the corresponding emitter is focused greater at the periphery than at the center of an emitter group.</p> |
