Scanning exposure apparatus
US5677754A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 15, 1995 |
| Grant date | Oct 14, 1997 |
| Priority date | — |
| Expiry date | Jun 15, 2015 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/70558
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A reticle is scanned in a predetermined direction relative to an illumination field of a predetermined shape. In synchronism therewith, a shot-area defined on a photo-sensitive substrate (or wafer) is scanned in the opposite direction relative to an exposure field which is optically conjugate to the illumination field. Through these scanning operations, a pattern formed on the reticle is transferred onto the shot-area on the photosensitive substrate. The illuminance of an illumination light is measured during a time period when the illumination field is in an acceleration region and before reaching the shot-area, and the amount of exposure onto the shot-area is controlled based on the results of the measurement. In this manner, the amount of exposure onto the photosensitive substrate can be controlled to the correct amount of exposure even when the illuminance of the illumination light for exposure tends to vary in a relatively short interval, while a reduction in the throughput of the exposure process can be prevented.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.