Scatterometer including an internal calibration system
US6795193B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Nov 26, 2002 |
| Grant date | Sep 21, 2004 |
| Priority date | — |
| Expiry date | Nov 30, 2022 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N21/956
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A scatterometer system comprises a pitch calibration station that allows the monitoring of a tool status of the scatterometry system without involving a user's interaction. The pitch calibration station comprises a pitch calibration standard, for example in the form of a grid pattern that may conveniently be evaluated on the basis of a reference data library. By providing the pitch calibration station, the measurement process may easily be adapted to include reference measurements on a regular basis so as to increase the reliability of measurement values obtained by scatterometry. In one particular example, a corresponding set of instructions for performing the calibration measurement may be implemented into a self-test routine of the scatterometry system.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.