Detection of an end point of polishing a substrate
US7003148B2 · kind B2 · utility
2Cited by
5References
6Claims
0Family size
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Key dates
| Filing date | Mar 4, 2002 |
| Grant date | Feb 21, 2006 |
| Priority date | — |
| Expiry date | Nov 25, 2023 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S438/959
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A two-dimensional image of a substrate surface targeted for polishing is periodically picked up, and the image is analyzed to obtain an entropy H1, H2 of the two-dimensional image. An end point of polishing is then determined according to the entropy H1, H2. Alternatively, other image characteristic value such as a difference statistic of the image may be employed instead of the entropy H1, H2.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.