Method of examining an exposure tool
US6317198A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 1, 1999 |
| Grant date | Nov 13, 2001 |
| Priority date | — |
| Expiry date | Jul 1, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/706
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
In a method of examining the shape of the light source of an exposure tool, the shape of the pupil of its projection optical system, and the alignment of the shape of the light source with the shape of the pupil, the exposure tool comprising a light source, an illumination optical system for directing the light emitted from the light source to a reticle, and a projection optical system for transferring the reduced image on the reticle onto a wafer, the light emitted from the light source is projected on a reticle including a grating pattern where a transmitting area and a shading area are repeated in a finite number, the diffracted light of the first order or higher passed through the reticle is caused to illuminate the outer edge of the pupil of the projection optical system, and the pattern image on the reticle is projected on the wafer in the defocus state.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.