Low net stress multilayer thin film coatings
US5930046A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 30, 1997 |
| Grant date | Jul 27, 1999 |
| Priority date | — |
| Expiry date | Sep 30, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B1/115
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
It has been discovered that control of the intra-layer stress in layers of high refractive index materials, such as zirconia and titania, permits low net stress multilayer thin film stacks comprising alternating layers of the high refractive index material and silica, a low refractive index material, to be sputter-deposited on glass substrates. In particular, a simple, cost-effective and readily reproducible post-deposition annealing process is used, i.e., an annealing process that can be effected within a broad temperature range and for a brief and substantially open-ended time period, to change the post-deposition microstructure of the high refractive index film layers and create a selected intra-layer tensile stress. The intra-layer tensile stress created during such an annealing process is largely dependent on the post-deposition microstructure of the high refractive index thin film layers. It has been further discovered that the deposition conditions and, in particular, ion bombardment energy, can be controlled to provide a selected and reproducible post-deposition microstructure that is partially amorphous and partially crystalline and which transforms during annealing to a v…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.