Electron gun and electron beam drawing apparatus using the same
US6593686B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Mar 29, 2000 |
| Grant date | Jul 15, 2003 |
| Priority date | — |
| Expiry date | Mar 29, 2020 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J2237/06308
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An electron gun according to this invention includes a cathode having a hemispherical electron-emitting surface, an anode which is arranged to face the cathode, and has a first aperture on the optical axis, and a bias electrode which is arranged between the anode and the cathode, receives a potential lower than one applied to the cathode, and has a second aperture larger than the electron-emitting surface of the cathode on the optical axis. The distal end of the electron-emitting surface of the cathode is arranged in contact with or outside a sphere whose diameter is equal to the diameter of the second aperture of the bias electrode.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.