Electron emitters for lithography tools
US6400090B2 · kind B2 · utility
8Cited by
4References
6Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Mar 27, 2001 |
| Grant date | Jun 4, 2002 |
| Priority date | — |
| Expiry date | Mar 27, 2021 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S430/143
- 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. A mesh grid is applied to the Wehnelt aperture and the mesh grid functions as a multiple secondary emitter to produce a uniform beam flux over a wide area. The grid voltage of the modified gun is substantially lower than in a conventional Wehnelt gun, i.e. less than 100 volts, which can be switched conveniently and economically using semiconductor drive circuits.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.