Exposure method and apparatus
US6433872B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 25, 1999 |
| Grant date | Aug 13, 2002 |
| Priority date | — |
| Expiry date | Mar 25, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F9/7026
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An apparatus for exposing a pattern, formed on a mask, on each of a plurality of partitioned areas on a photosensitive substrate by a step-and-repeat scheme includes a projection optical system for projecting the pattern of the mask on the photosensitive substrate, a substrate stage for holding the photosensitive substrate and two-dimensionally moving the photosensitive substrate within a plane perpendicular to the optical axis of the projection optical system, a detection unit for projecting a pattern image having a predetermined shape on the photosensitive substrate and photoelectrically detecting light reflected by the photosensitive substrate to detect a position at each of a plurality of points on the photosensitive substrate along the optical axis of the projection optical system, and a measurement unit for, when each of a plurality of measurement points in a partitioned area on which a pattern of the mask is to be exposed next coincides with or approaches the pattern image, detecting an offset amount between an imaging plane of the projection optical system and the next partitioned area along the optical axis during a stepping operation of the substrate stage, wherein the im…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.