Synthetic quartz glass member for use in ArF excimer laser lithography
US6480518B1 · kind B1 · utility
Assignees
Inventors
Key dates
| Filing date | Mar 3, 2000 |
| Grant date | Nov 12, 2002 |
| Priority date | — |
| Expiry date | Mar 3, 2020 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC03C2203/50
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A synthetic glass member for use in excimer laser lithography, having superior homogeneity, high transmittance for ArF excimer laser beams and an excellent resistance against lasers is made from high purity synthetic quartz glass, and it is characterized in that layered structures, striae in three directions and internal strains are thermally and mechanically removed, the distribution of refractive index (&Dgr;n) in a plane orthogonal to the optical axis is up to about 1×10−6, the distribution of refractive index (&Dgr;n) in a plane parallel to the optical axis is up to about 5×10−6, the birefringence is up to about 2 nm/cm, the hydrogen molecule concentration is at least about 2×1017 molecules/cm3, and the internal transmittance is at least about 99.8% at a wavelength of 193.4 nm.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.