Weighting function to enhance measured diffraction signals in optical metrology
US7523021B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 8, 2006 |
| Grant date | Apr 21, 2009 |
| Priority date | — |
| Expiry date | Apr 12, 2027 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01B11/24
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A weighting function is obtained to enhance measured diffraction signals used in optical metrology. To obtain the weighting function, a measured diffraction signal is obtained. The measured diffraction signal was measured from a site on a wafer using a photometric device. A first weighting function is defined based on noise that exists in the measured diffraction signal. A second weighting function is defined based on accuracy of the measured diffraction signal. A third weighting function is defined based on sensitivity of the measured diffraction signal. A fourth weighting function is defined based on one or more of the first, second, and third weighting functions.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.