| 摘要 |
PURPOSE:To enhance the picture quality by fitting a reflex electron diffuse plate between an objective lens and a secondary electron sensor, and hindering the reflex electrons generated from a solid specimen from incidence again to the specimen, or reducing the amount of reflex electrons incident again to the specimen. CONSTITUTION:On the surface of a reflex electron diffuse plate 6, electrons B reflected at a specimen X are diffused as shown by C so as not to make incidence again to the specimen X easily, and the surface shall be processed uneven for the beam no to make direct incidence to a secondary electron emitting device 5. This diffuse plate 6 consists either of single structure of metal, ceramic, organic substance, etc., or of a multi-layer structure in combination of metal, ceramic, organic substance, etc., and its surface is formed from good electroconductive material. The diffuse plate 6 is off contact from the device body electrically, and the surface is charged, for ex., at 3-5V to trap the secondary electrons b generated at the diffuse plate 6 for the secondary electron sensor 5 not to catch them. Thus the picture quality is enhanced by trapping the secondary electrons b and reducing the secondary electrons due to reflex electrons which have made reincidence by the specimen X. |
