Visual inspection and verification system
US6757645B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 7, 1998 |
| Grant date | Jun 29, 2004 |
| Priority date | — |
| Expiry date | Aug 7, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06T2207/30148
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A method and apparatus for inspecting a photolithography mask for defects is provided. The inspection method comprises providing a defect area image to an image simulator wherein the defect area image is an image of a portion of a photolithography mask, and providing a set of lithography parameters as a second input to the image simulator. The defect area image may be provided by an inspection tool which scans the photolithography mask for defects using a high resolution microscope and captures images of areas of the mask around identified potential defects. The image simulator generates a first simulated image in response to the defect area image and the set of lithography parameters. The first simulated image is a simulation of an image which would be printed on a wafer if the wafer were to be exposed to an illumination source directed through the portion of the mask. The method may also include providing a second simulated image which is a simulation of the wafer print of the portion of the design mask which corresponds to the portion represented by the defect area image. The method also provides for the comparison of the first and second simulated images in order to determine t…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.