Exposure apparatus and exposure method for minimizing defocusing of the transferred pattern
US5640227A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 6, 1994 |
| Grant date | Jun 17, 1997 |
| Priority date | — |
| Expiry date | Dec 6, 2014 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/70358
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An exposure apparatus and an exposure method which minimize defocusing of the transferred pattern even with a large-sized mask. When the exposure apparatus is used which transfers the pattern formed on a first substrate through a substantially real-size projection optical system onto a second substrate, the positions of the mask and the substrate are detected, and based on the information on the positions the distance between the mask and the substrate is controlled to be substantially constant. According to the present invention, defocusing of the transferred pattern may be substantially avoided by detecting positions of the mask and the plate by making use of, e.g., an obliquely incident light focus detection optical system, and controlling the distance therebetween to be held constant or at a predetermined distance.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.