Projection exposure apparatus, method for correcting positional discrepancy of projected image, and method for determining image formation characteristic of projection optical system
US5999244A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 4, 1996 |
| Grant date | Dec 7, 1999 |
| Priority date | — |
| Expiry date | Nov 4, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/70691
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
Positional discrepancies of images of segmental areas, which are caused by stretching of a substrate in the Y direction, are corrected by changing magnifications of respective projection optical systems and inclinations of parallel plane glass pieces with respect optical axes. After that, positional discrepancies of the images after the correction are accurately detected by using a calibration system for the projection optical systems. Thus it is possible to confirm whether or not the positional discrepancies are accurately corrected. If the correction is insufficient as a result of the confirmation, at least one of correction of the magnifications of the respective projection optical systems and shift of the images projected through the respective projection optical systems onto the substrate is executed again so that amounts of the positional discrepancies are sufficiently small. On the other hand, the positional discrepancy can be easily determined by storing positional information and a detected signal concerning an image formed by a projection optical system in synchronization with a clock, followed by signal processing.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.