Method for finishing surface of preliminary polished glass substrate
US7998645B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 14, 2010 |
| Grant date | Aug 16, 2011 |
| Priority date | — |
| Expiry date | Jun 14, 2030 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/24355
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A glass substrate obtained by a method including measuring flatness of a glass substrate surface and measuring concentration distribution of dopant in the substrate. Processing conditions of the surface are set up for each site of the substrate based on results from the measuring the flatness and the measuring the distribution, and the finishing is carried out while keeping an angle formed by normal line of the substrate and incident beam onto the surface at from 30 to 89°. The surface is subjected to second finishing for improving an RMS in a high spatial frequency region. The surface after the second finishing satisfies the requirements: an RMS slope in the region that 5 μm<λ(spatial wavelength)<1 mm is not more than 0.5 mRad and an RMS slope in the region that 250 nm<λ(spatial wavelength)<5 μm is not more than 0.6 mRad.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.