Wafer inspection with focus volumetric method
US9816940B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 19, 2016 |
| Grant date | Nov 14, 2017 |
| Priority date | — |
| Expiry date | Jan 19, 2036 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2021/8887
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Disclosed are methods and apparatus for detecting defects in a semiconductor sample. An inspection tool is used to collect intensity data sets at a plurality of focus settings from each of a plurality of xy positions of the sample. A polynomial equation having a plurality of coefficients is extracted for each of the xy position's collected intensity data sets as a function of focus setting. Each of the coefficients' set of values for the plurality of xy positions is represented with a corresponding coefficient image plane. A target set of coefficient image planes and a reference set of coefficient image planes are then analyzed to detect defects on the sample.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.