Projection exposure apparatus
US5117254A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 8, 1991 |
| Grant date | May 26, 1992 |
| Priority date | — |
| Expiry date | May 8, 2011 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F9/7026
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A projection exposure apparatus including a mask stage for supporting a mask, a wafer stage for supporting a wafer, and a projection optical system for projecting, on the wafer, an image of a circuit pattern of the mask, is disclosed. There are provided a surface position detecting system for detecting position of a surface of the water with respect to a direction of an optical axis of the projection optical system, an adjusting device for adjusting an interval between the wafer and the projection optical system, to position the wafer surface at a focus position of the projection optical system, and an outputting portion operable to direct a light beam to a reflection surface, provided at a predetermined site on the wafer stage, and to receive reflection light coming from the reflection surface through the projection optical system, the outputting portion producing a signal corresponding to a positional relationship between the reflection surface and the focus position of the projection optical system. A focus position detecting system detects the focus position of the projecting optical system, on the basis of the signal from the outputting portion, and a control system controls t…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.