Qualification of a mask
US7330249B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 30, 2006 |
| Grant date | Feb 12, 2008 |
| Priority date | — |
| Expiry date | Oct 30, 2026 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04W8/18
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A method for qualifying printability of a mask, including performing a first inspection of the mask with an optical assembly at a first numerical aperture of collection (NAC) of radiation from the mask, and determining, in response to the first inspection, a first possible defect in the mask and a first location of the first possible defect. The method also includes performing a second inspection of the mask with the optical assembly at a second NAC of radiation from the mask, different from the first NAC, and determining, in response thereto, a second possible defect in the mask and a second location of the second possible defect. The method further includes performing a comparison of the first and second locations, and in response to the comparison, determining that the first and second possible defects represent a real defect if the first location matches the second location.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.