Using thin films as etch stop in EUV mask fabrication process
US5958629A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 22, 1997 |
| Grant date | Sep 28, 1999 |
| Priority date | — |
| Expiry date | Dec 22, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F1/80
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A silicon-substrate based reflective photolithographic mask fabrication technique is described. The process begins with a multilayer, resonant reflecting substrate. A thin layer of silicon dioxide or other material capable of acting as an etch stop layer is deposited thereon. Then, a transmissive layer is deposited on the thin layer of etch stop layer. The transmissive layer is substantially transmissive to the wavelength of light used in the photolithography as well as capable of being selectively etched relative to the underlying etch stop layer. Then, the transmissive layer is etched to open preselected, absorptive areas. An absorptive layer is then deposited thereon. The absorptive layer is substantially absorptive to the wavelength of light used as well as capable of completely filling the opened areas of the transmissive layer. The absorptive layer is then planarized, and a thin protective cap is deposited thereon.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.