Optimization method of aperture type of projection aligner
US6999160B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Sep 30, 2003 |
| Grant date | Feb 14, 2006 |
| Priority date | — |
| Expiry date | May 14, 2024 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/70125
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
In a method of optimizing a shape of an aperture, an effective light source is divided into a plurality of minute areas having same shape and size. One point light source is provided at a center of each of the divided minute areas. A normalized image light intensity slope on a wafer is obtained in consideration of a focus variation of a projection aligner for a plurality of patterns at each of the point light sources. The normalized image light intensity slope of a light intensity is used as an index. The image light intensity slope is related to an exposure amount variation of the projection aligner by one dimensional function. A common opening is selected for the shape of the aperture that is optimized for each of the patterns. The common opening is made into an optimum shape of the aperture for the patterns.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.