Projection exposure apparatus and method
US6400441B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 20, 2000 |
| Grant date | Jun 4, 2002 |
| Priority date | — |
| Expiry date | Sep 20, 2020 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F9/7088
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
Two stages (WS1), (WS2) holding wafers can independently move between a positional information measuring section (PIS) under an alignment system (24a) and an exposing section (EPS) under a projection optical system (PL). The wafer exchange and alignment are performed on the stage (WS1), during which wafer (W2) is exposed on the stage (WS2). A position of each shot area of wafer (WS1) is obtained as a relative position with respect to a reference mark formed on the stage (WS1) in the section (PIS). Relative positional information can be used for the alignment with respect to an exposure pattern when the wafer (WS1) is moved to the section (EPS) to be exposed. Therefore, it is not necessary that a stage position is observed continuously in moving the stage. Exposure operations are performed in parallel by the two wafer stages (WS1) and (WS2) so as to improve the throughput.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.