Electron guns for lithography tools
US6492647B1 · kind B1 · utility
2Cited by
11References
10Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | May 7, 1999 |
| Grant date | Dec 10, 2002 |
| Priority date | — |
| Expiry date | May 7, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J2237/31791
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
The specification describes a method and apparatus for electron beam lithography wherein a Wehnelt electron gun is modified to improve the uniformity of the electron beam. The bias on the Wehnelt aperture is reversed from the conventional bias so that it is biased positively with respect to the cathode. The Wehnelt opening is tapered with a disk emitter inserted into the taper. The result of these modifications is an electron beam output with low brightness which is highly uniform over the beam cross section.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.