Phase shift mask, method of correcting the same and apparatus for carrying out the method
US5358806A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 19, 1992 |
| Grant date | Oct 25, 1994 |
| Priority date | — |
| Expiry date | Mar 19, 2012 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J2237/30466
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A defect of a phase shift mask, which has a phase shifter disposed on a transparent substrate, formed into a predetermined pattern and acting to shift a phase of exposure light transmitted therethrough and an etching stopper disposed between the phase shifter and the transparent substrate, which is resistant to an etching to which the phase shifter is subjected and transparent for exposure light is corrected by selectively etching a defective portion of the phase shifter, having a lacking type defect, with respect to the etching stopper layer along the whole thickness of the phase shifter and by perforating a portion of the etching stopper layer and the transparent substrate positioned under the etched defective portion by a depth which corresponds to a magnitude of an optical path of the phase shifter for the exposure light, the etching being a reactive etching which uses charged particle beam and a reactive gas and, the bottom surface of a portion etched being flattened by utilizing a fact that the phase shifter is selectively etched.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.