Light irradiation control method for projection exposure apparatus
US4624551A · kind A · utility
20Cited by
2References
20Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Oct 28, 1985 |
| Grant date | Nov 25, 1986 |
| Priority date | — |
| Expiry date | Oct 28, 2005 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/70891
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A control method for the projection optical system of a projection exposure apparatus used in the fabrication of LSIs. The amount of energy incident to the projection optical system during each unit time is maintained constant at all times including each projection and the intervals between the projection operations. This has the effect of cancelling any error in the projected image, particularly any variation of the magnification error with time due to any variation of the optical performance of the projection optical system caused by the illuminating energy.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.