Projection exposure apparatus and method with workpiece area detection
US6191429A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Apr 6, 1999 |
| Grant date | Feb 20, 2001 |
| Priority date | — |
| Expiry date | Apr 6, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F9/7026
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
Improvements in a focusing apparatus having an objective optical system for optically manufacturing a workpiece, forming a desired pattern on a surface of a workpiece or inspecting a pattern on a workpiece and used to adjust the state of focusing between the surface of the workpiece and the objective optical system. The focusing apparatus has a first detection system having a detection area at a first position located outside the field of the objective optical system, a second detection system having a detection area at a second position located outside the field of the objective optical system and spaced apart from the first position, and a third detection system having a detection area at a third position located outside the field of the objective optical system and spaced apart from each of the first and second positions. A calculator calculates a deviation between a first focus position and a target focus position and temporarily stores a second focus position at the time of detection made by the first detection system. A controller controls focusing on the surface of the workpiece on the basis of the calculated deviation, the stored second focus position and a third focus posi…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.