Mask inspection with fourier filtering and image compare
US9041903B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 18, 2010 |
| Grant date | May 26, 2015 |
| Priority date | — |
| Expiry date | Dec 23, 2031 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F1/84
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A mask inspection system with Fourier filtering and image compare can include a first detector, a dynamic Fourier filter, a controller, and a second detector. The first detector can be located at a Fourier plane of the inspection system and can detect a first portion of patterned light produced by an area of a mask. The dynamic Fourier filter can be controlled by the controller based on the detected first portion of the patterned light. The second detector can detect a second portion of the patterned light produced by the section of the mask and transmitted through the dynamic Fourier filter. Further, the mask inspection system can include a data analysis device to compare the second portion of patterned light with another patterned light. Consequently, the mask inspection system is able to detect any possible defects on the area of the mask more accurately and with higher resolution.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.