Projection lithography on curved substrates
US6416908B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 29, 2000 |
| Grant date | Jul 9, 2002 |
| Priority date | — |
| Expiry date | Oct 31, 2020 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/703
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A microlithography system, capable of performing high resolution imaging on large-area curved surfaces, based on projection lithography. The system utilizes a high-resolution lens to image a curved mask directly onto a curved substrate. The system uses a curved mask which is identical in shape to the curved substrate, in order to achieve a constant track length for conjugate object and image points, thereby maintaining focus over the full area of curved substrates having height variations that greatly exceed the depth-of-focus of the imaging lens. Magnification errors are controlled by continuous adjustments of the z-position of the projection lens during scanning, with the adjustments depending upon the topography of the curved mask and substrate. By performing the lithography using a step-and-scan seamless-patterning microlithography system, it is possible to pattern over large areas, greater than the field size of the lens. When the mask and substrate are mounted on a common scanning platform, the system operates with an inverted mask. The system also has provisions for making the appropriate curved projection masks, using a planar contact printing technique to pattern high-reso…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.