Control of a distribution of illumination in an exit pupil of an EUV illumination system
US6704095B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Jan 30, 2002 |
| Grant date | Mar 9, 2004 |
| Priority date | — |
| Expiry date | Jan 30, 2022 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S359/90
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
There is provided an illumination system for a projection exposure system. The illumination system includes (a) a light source for the emission of wavelengths of ≦193 nm, (b) a device for producing secondary light sources, the device including a mirror having raster elements, (c) a diaphragm plane, (d) a first optical element for imaging the diaphragm plane in an exit pupil of the illumination system, (e) an object plane in which images of the raster elements are substantially in line and illuminate a predetermined field with an intensity distribution, and (f) a second optical element for producing a light distribution in the exit pupil. The light distribution is specified by a parameter selected from the group consisting of type and filling degree, and the parameter is modified by a technique selected from the group consisting of exchanging, displacing and deforming the second optical element.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.