| 摘要 |
<p>PURPOSE:To improve reliability with an electric field made concentrative, operating voltage reduced, and mechanical strength improved by forming an emitter projection on a part tilted to a gate electrode side and supporting the tilted part of an emitter from the back. CONSTITUTION:A tilted part 14, expandedly opened gradually toward the upper stage 13 side, is formed on the lower stage part 12 side of an insulating substrate 11, and a cavity part 15 is formed in a space with the upper stage part 13 outside the tilted part 14. An emitter 16, composed of Mo, W, and Cr, etc., is formed on the lower stage part 12 and the continued tilted part 14, and a gate electrode 17, composed of the same material, is formed on the upper stage part 13. In the emitter 16, its tilted part is tilted on the electrode 17 side along the tilted part 14 of the substrate 11, and an emitter projection 18 is formed on the tip part of the emitter 16. Application of negative voltage to the emitter 16 and of positive voltage to the electrode 17 causes efficient electron emission from the projection 18. An orbit of electrons is decided along an electric force line with the electrode 17 and the emitter 16 and electron beam expansion can be restrained.</p> |
