Method of lithography using vacuum ultraviolet radiation
US6605815B2 · kind B2 · utility
Inventor
Key dates
| Filing date | Mar 11, 2002 |
| Grant date | Aug 12, 2003 |
| Priority date | — |
| Expiry date | Mar 11, 2022 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/70575
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A method of vacuum ultraviolet (VUV) lithography in which an irradiating wavelength is selected to be in a region of low absorption in air, e.g., one in the vicinity of a local minimum in an oxygen absorption spectrum. In one embodiment, a lithographic exposure wavelength is advantageously selected between 121.0 nm to 122.0 nm, preferably at about 121.6 nm, corresponding to an absorption window in the oxygen spectrum. This method relaxes the otherwise stringent vacuum and inert gas purge requirement imposed on a VUV lithographic tool.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.