X-ray transmitting membrane for mask in x-ray lithography and method for preparing the same
US5326649A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 26, 1992 |
| Grant date | Jul 5, 1994 |
| Priority date | — |
| Expiry date | Mar 26, 2012 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/24488
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
Disclosed is an X-ray transmitting frame-supported membrane of silicon nitride suitable as a mask blank of an X-ray lithographic mask having outstandingly high resistance against irradiation with high-energy radiations and high transmission of light of a wavelength of 633 nm. These very desirable properties are obtained as a consequence of the extremely low content, i.e. 1.0 atomic % or less, of hydrogen in the silicon nitride, which can be achieved as a result of the specific preparation procedure by the CVD method in which the reactant gases are silane or disilane and ammonia in a specified mixing ratio to be reacted under a specified pressure and at a specified temperature.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.