Method of measuring exposure condition and/or aberration of projection optical system
US5814425A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 29, 1995 |
| Grant date | Sep 29, 1998 |
| Priority date | — |
| Expiry date | Aug 29, 2015 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/706
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A method of measuring an exposure condition for transfer of a pattern onto a photosensitive substrate or aberration of a projection optical system is disclosed, wherein the pattern is transferred onto the photosensitive substrate plural times in different exposure conditions, to form photosensitive patterns on the photosensitive substrate, and images of the photosensitive patterns are picked up. Frequency components of the photosensitive patterns are calculated from corresponding imagewise signals, and an optimum exposure condition for transfer of the pattern onto the photosensitive substrate is determined on the basis of the frequency components of the photosensitive patterns.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.