Method and apparatus for shaping a laser-beam intensity profile by dithering
US6341029B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 27, 1999 |
| Grant date | Jan 22, 2002 |
| Priority date | — |
| Expiry date | Apr 27, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/70375
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
In an optical-radiation patterning apparatus, a scan mirror (29) so deflects laser light from a source (32) as to draw a pattern on a substrate (26). A focusing system (42) forms a light spot on the substrate that is significantly narrower than the line to be drawn, and it thereby minimizes the sensitivity of the line-edge position to variations in light-spot size. To achieve the intended line width, an acousto-optical device (32) introduces dither in the direction orthogonal to the light-spot motion that the scan mirror (30) causes. The focusing system (42) shapes the spot so that it is wider in the scan direction than it is in the dither direction, and this permits a relatively high scan rate for a given dither frequency.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.