Raster shaped beam, electron beam exposure strategy using a two dimensional multipixel flash field
US6262429A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 6, 1999 |
| Grant date | Jul 17, 2001 |
| Priority date | — |
| Expiry date | Jan 6, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J2237/31776
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An electron beam column (or other charged particle beam column) for lithography which exposes a surface to variable shapes in a raster scan. The beam column includes an electron (or ion) source that generates a charged particle beam, a transfer lens, an upper aperture, an upper deflector, a lower aperture, a lower deflector, magnetic deflection coils, and a beam objective lens. The beam is first shaped as a square in cross section by the upper aperture. The upper deflector changes the direction of the square shaped beam to pass through a specific portion of an opening defined in the lower aperture to shape the beam as desired. The lower aperture defines either a cross shaped opening or four L-shaped openings arranged as corners of a square. The combination of upper and lower apertures enable definition of exterior and interior corners as well as horizontal and vertical edges of a pattern, so that only one flash need be exposed in any one location on the surface. The lower deflector reverses any change in direction imposed by the upper deflector and further applies a retrograde scan to counteract a movement of the beam by the magnetic coils in a raster scan. The retrograde scan ensu…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.