Projection type exposure apparatus
US4498762A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 20, 1982 |
| Grant date | Feb 12, 1985 |
| Priority date | — |
| Expiry date | Dec 20, 2002 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F9/7049
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A projection type exposure apparatus has a projection objective lens, a projection negative having a predetermined shape pattern and an alignment mark, and a photosensitive plate having an alignment mark. The shape pattern of the projection negative is projected upon the photosensitive plate by the projection objective lens. Main illuminating optical means illuminates the projection negative with a first wavelength light to which the photosensitive plate is sensitive, and alignment optical means illuminates the projection negative with a second wavelength light to which the photosensitive plate is insensitive. The positional relation between the projection negative and the photosensitive plate is detected using the second wavelength light through the projection objective lens. One of the alignment mark on the projection negative and the alignment mark on the photosensitive plate has a zone pattern which forms a light-condensing point at a position spaced apart by a predetermined amount from the surface on which said one mark is formed, and said predetermined amount corresponds to the amount of chromatic aberration of the projection objective lens, at the side thereof adjacent to sa…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.