Exposure apparatus and method of controlling the same
US6501532B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Dec 17, 1998 |
| Grant date | Dec 31, 2002 |
| Priority date | — |
| Expiry date | Dec 17, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03B27/34
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
In a step and repeat process with a projection exposure apparatus, a pre-auto focus process is performed so as to compensate for a focus error caused by traveling of an XY stage wherein the pre-auto focus process is performed in a period in which the XY stage is moved from one exposure location to another. The pre-auto focus process minimizes the focus error, which is further corrected in a focus adjustment process using an auto focus sensor. This technique allows a focus adjustment to be made with improved accuracy in a short time. The focus error corrected in the pre-auto focus process is such an error of the position, in a direction along the optical axis, of the exposure surface with respect to the projection image plane that occurs when the XY stage is driven in a plane that is not parallel to the projection image plane and that is proportional to the traveling distance of the XY stage in the XY plane.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.