Protected pattern mask for reflection lithography in the extreme UV or soft X-ray range
US7763394B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Jan 26, 2005 |
| Grant date | Jul 27, 2010 |
| Priority date | — |
| Expiry date | Apr 14, 2026 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F1/62
- WIPO fieldMicro-structural and nano-technology
- WIPO sectorChemistry
Abstract
A mask (MM) with patterns (MF) for use in a reflection lithography device with a photon beam with a wavelength of less than about 120 nm. Said mask (MM) comprises a planar substrate (ST) fixed to a reflecting structure (SMR) comprising a front face provided with selected patterns (MF) made from a material which is absorbent at the given wavelength and further comprises protection means (SP) which are transparent to the given wavelength and arranged such as to maintain a distance (H) between the perturbing particles (PP) and the patterns (MF) greater than or equal to one of the values of the depth of focus of the lithographic device and the height associated with the percentage of photon absorption by the perturbing particles (PP) which is acceptable.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.