Exposure apparatus and method wherein alignment is carried out by comparing marks which are incident on both reticle stage and wafer stage reference plates
US5751404A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 22, 1996 |
| Grant date | May 12, 1998 |
| Priority date | — |
| Expiry date | Jul 22, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F9/7015
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A scanning exposure apparatus includes a first movable stage being movable while carrying a first object thereon, a second movable stage being movable while carrying a second object thereon, a projection optical system for projecting a pattern, a control system serviceable to scan the first and second movable stages in a timed relation and relative to the projection optical system and to project a pattern of the first object onto the second object through the projection optical system, a first reference plate fixedly mounted on the first movable stage, a second reference plate fixedly mounted on the second movable stage, and a detecting system serviceable to scan at least one of the first and second movable stages to detect a relative positional relationship between alignment marks of the first and second reference plates to thereby determine a scan direction of one of the first and second movable stages.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.