Projection-microlithographic device
US6445442B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 20, 2001 |
| Grant date | Sep 3, 2002 |
| Priority date | — |
| Expiry date | Aug 20, 2021 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/70358
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An illuminating device of a projection-microlithographic device includes a light source, an objective, and a device which produces a particular image field configuration. The device has fields which, in the direction of scanning movement, are separated at least in parts by a free zone, and are located in a peripheral region of the circular image field of a downstream projection objective in a manner at least approximating rotation symmetry. The integral of the quantity of light passing through the fields in the scanning direction are constant over the entire extent of the image field configuration in the direction at right angles to the scanning direction. Such an image field configuration replaces a conventional rectangular scanner slot formation whose width in the scanning direction corresponds to the forementioned integral of the image field configuration. The design of the image field configuration permits an approximately rotationally symmetric illumination of the projection objective.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.