| 摘要 |
<p>PURPOSE:To obtain a stable performance in an electron gun and improve its durability, by engaging and fixing a tip made of lanthanum boride to the hollowed part of a graphite tip with the hollowed part on its one side simultaneously with the coating of a material having a high melting point on its all sides. CONSTITUTION:An electron gun used in an electron microscope or electron beam exposure device is constituted by an anode, Wehnelt electrode 5 and a tip 1 made of lanthanum boride used as a cathode. The lanthanum boride tip 1 is engaged and fixed into a hollowed part 2b provided in an graphite tip 2 held between support electrodes 3 having an adjustment screw 4. As the graphite tip 2 a material, coated with those having a high melting point like silicon carbide, boron carbide or the like on its all sides except both end sides (contacted portions to the support electrodes 3), is used.</p> |
