Optimized capping layers for EUV multilayers
US6780496B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 1, 2002 |
| Grant date | Aug 24, 2004 |
| Priority date | — |
| Expiry date | Mar 28, 2022 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/31678
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A new capping multilayer structure for EUV-reflective Mo/Si multilayers consists of two layers: A top layer that protects the multilayer structure from the environment and a bottom layer that acts as a diffusion barrier between the top layer and the structure beneath. One embodiment combines a first layer of Ru with a second layer of B4C. Another embodiment combines a first layer of Ru with a second layer of Mo. These embodiments have the additional advantage that the reflectivity is also enhanced. Ru has the best oxidation resistance of all materials investigated so far. B4C is an excellent barrier against silicide formation while the silicide layer formed at the Si boundary is well controlled.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.