| 摘要 |
<p>PURPOSE: To suppress an abnormal discharge or leakage current and stabilize electron emitting characteristic by setting the distance between emitter anodes other than an electron emitting part sufficiently large, or putting an insulating material between them to stabilize the surface. CONSTITUTION: A conical emitter 42 consisting of Mo is provided on a Si base 41, and an insulating layer 44 such as silicon oxide having an opening part 482 is formed around it. An anode 43 having one end part near the top end of the emitter 42 is formed thereon. Differed from a conventional case, the other end of the anode 43 is positioned closer to the inside from the end of the insulating layer 44. The difference between the end of the anode 43 and the end of the insulating material 44 is set to a value such that the distance laid along the surface layer of the insulating layer 44 is sufficiently large that no discharge is caused even when a voltage is applied between the Si base 41 and the anode 43. When an electron emitting element is placed in vacuum, and a voltage is applied between the base 41 and the anode 43, electrons are emitted from the top end part of the emitter 42 having a high field intensity. Since the distance between the outer end of the anode 43 and the side surface exposed part of the base 41 is large, no discharge is caused in the peripheral part to stabilize the operation.</p> |
