Electron beam blanker
US4445041A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 2, 1981 |
| Grant date | Apr 24, 1984 |
| Priority date | — |
| Expiry date | Jun 2, 2001 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/30
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An electron beam blanker for use in electron beam lithography systems is disclosed which is capable of providing exposure rates on the order of 300MHz at beam currents of approximately 600nA. A condensing lens and a stigmator are provided to bring the electron beam to a small image in a plane perpendicular to the beam direction. An etched silicon knife-edge, coated with gold, is located in this image plane in close proximity to the beam, to provide a sharp cut-off as the beam is swept past its edge. In accordance with aspects of the invention, a deflector plate structure provides an electromagnetic field whose geometry ensures that the velocity of a beam electron, as it exits the field, is substantially directly proportional to the undeflected beam electron's position vector relative to the beam cross-over in the image plane of the condenser lens. Since the image plane of the condensing lens becomes the object plane for a final lens which forms the spot on a point on the resist, the above geometry substantially eliminates spot motion during the blanker rise time.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.