Four-layer antireflection coating for deposition in in-like DC sputtering apparatus
US5450238A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 10, 1993 |
| Grant date | Sep 12, 1995 |
| Priority date | — |
| Expiry date | Dec 10, 2013 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC03C17/3417
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
An antireflection coating for a substrate including four layers and having optimized photopic reflectance and optimized for deposition by sputtering. The first layer (the layer farthest from the substrate) has a refractive index less than the refractive index of the substrate and a thickness of about one-quarter wavelength. The second layer (the layer adjacent the first layer) has an refractive index greater than about 2.2 and a thickness of about a half wavelength. The third layer has refractive index less than that of the second layer. The fourth layer (the layer adjacent the substrate) has a refractive index less than about 2.0 and greater than that of the third layer. The combined thickness of the third and fourth layers is less than about a quarter wavelength. The first and third layers may include silicon dioxide. The second layer may include titanium dioxide or niobium oxide. The fourth layer may include indium oxide, tin oxide, indium tin oxide, or zinc oxide.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.