Extreme ultraviolet soft x-ray projection lithographic method and mask devices
US6465272B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 13, 2000 |
| Grant date | Oct 15, 2002 |
| Priority date | — |
| Expiry date | Sep 18, 2020 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S438/974
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
The present invention relates to reflective masks and their use for reflecting extreme ultraviolet soft x-ray photons to enable the use of extreme ultraviolet soft x-ray radiation projection lithographic methods and systems for producing integrated circuits and forming patterns with extremely small feature dimensions. The projection lithographic method includes providing an illumination sub-system for producing and directing an extreme ultraviolet soft x-ray radiation &lgr; from an extreme ultraviolet soft x-ray source; providing a mask sub-system illuminated by the extreme ultraviolet soft x-ray radiation &lgr; produced by the illumination sub-system and providing the mask sub-system includes providing a patterned reflective mask for forming a projected mask pattern when illuminated by radiation &lgr;. Providing the patterned reflective mask includes providing a Ti doped high purity SiO2 glass wafer with a patterned absorbing overlay overlaying the reflective multilayer coated Ti doped high purity SiO2 glass defect free wafer surface that has an Ra roughness≦0.15 nm. The method includes providing a projection sub-system and a print media subject wafer which has a radiation sens…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.