Diffractive element in extreme-UV lithography condenser
US6118577A · kind A · utility
40Cited by
11References
26Claims
0Family size
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Key dates
| Filing date | Aug 6, 1998 |
| Grant date | Sep 12, 2000 |
| Priority date | — |
| Expiry date | Aug 6, 2018 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S359/90
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
Condensers having a mirror with a diffraction grating in projection lithography using extreme ultra-violet significantly enhances critical dimension control. The diffraction grating has the effect of smoothing the illumination at the camera's entrance pupil with minimum light loss. Modeling suggests that critical dimension control for 100 nm features can be improved from 3 nm to less than about 0.5 nm.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.