Density-aware dynamic leveling in scanning exposure systems
US7239371B2 · kind B2 · utility
7Cited by
8References
13Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Oct 18, 2005 |
| Grant date | Jul 3, 2007 |
| Priority date | — |
| Expiry date | Jan 6, 2026 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F9/7026
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A method and apparatus are provided for improving the leveling and, consequently, the focusing of a substrate such as a wafer during the photolithography imaging procedure of a semiconductor manufacturing process. The invention performs a pre-scan of the wafer's topography and assigns importance values to different regions of the wafer surface. Exposure focus instructions are calculated based on the topography and importance values of the different regions and the wafer is then scanned and imaged based on the calculated exposure focus instructions.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.