Small field scanner
US5255051A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jan 5, 1993 |
| Grant date | Oct 19, 1993 |
| Priority date | — |
| Expiry date | Jan 5, 2013 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/70725
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A method and apparatus for printing arbitrarily large circuit patterns using small field optics. The use of small field imaging optics allows the use of high NA lens designs capable of printing smaller geometries than otherwise would be possible. The field size in a first axis is extended by scanning an object and image past the lens; the field size in a second axis is extended by stitching the scans together in an overlapped fashion. This overlapped printing technique averages many random and systematic errors and allows the placement of field adjacencies within die boundaries. The effective field size of such a system is limited only by reticle size and stage mechanics. The apparatus further includes error correction loops for enhancing stage synchronization accuracy and for reducing field adjacency errors.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.