Method and apparatus for multi-stream detection of high density metalization layers of multilayer structures having low contrast
US6005966A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Feb 12, 1997 |
| Grant date | Dec 21, 1999 |
| Priority date | — |
| Expiry date | Feb 12, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N21/956
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method and apparatus for detecting opens and shorts in a metalization layer includes creating a reference feature list of opens features and at least two reference feature lists of shorts features included in a top surface metalization. A first of the at least two reference feature lists include shorts features having a first threshold and the second of the at least two reference feature lists include shorts features having a second threshold more aggressive than the first threshold. High numerical aperture (NA) illumination is used to produce a grey level image of the top surface metalization. A first image stream is produced from the grey level image using a first digital threshold suitable for use in detecting opens exclusive of shorts and then opens features are extracted. At least a second image stream and a third image steam are then produced from the grey level image using second and third digital thresholds, respectively, suitable for use in detecting shorts exclusive of opens. Thereafter, shorts features are extracted from the second and third image streams. Lastly, a report of extra opens features and extra shorts features extracted from the first, second, and third ima…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.