| 摘要 |
PURPOSE:To reduce the amounts of sputter particles and secondary electrons emitted from the lead-out electrode and achieve effectual utilization of a charged particle beam by usin a metallic net or a ring-like electrode as the charged-particle leading-out electrode. CONSTITUTION:An ion-leading-out electrode 5 consists of a metallic net or a ring electrode. The metallic net is prepared from a tungsten net of 50 mesh having a transmission factor of 80%. The wire diameter of the ring electrode is 1mm.phi and its ring diameter is 10mm.phi. Firstly, an emitter chip 1 and a crucible 2 are heated to above the melting point of an ion source material 3 to supply the molten ion source material 3 to the pointed end of the emitter chip 1. Next, an ion-leading-out voltage is applied to the ion-leading-out electrode 5 to lead ions emitted by an electric field. By the means mentioned above, it is possible to reduce the amounts of sputter particles and secondary electrons emitted from the lead-out electrode 5 and to effectually utilize a charged particle beam. |
