Methods and devices for reducing errors in Goos-Hänchen corrections of displacement data
US8842296B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 13, 2013 |
| Grant date | Sep 23, 2014 |
| Priority date | — |
| Expiry date | Mar 13, 2033 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/00
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An exemplary method involves, in a system comprising a tool that performs a task on a workpiece, a method for determining displacement of the workpiece relative to the tool. Respective displacements of loci of at least a region of the workpiece are mapped using a Goos-Hänchen-insensitive (GH-insensitive) displacement sensor to produce a first set of physical displacement data for the region. Also mapped are respective displacements, from the tool, of the loci using a GH sensitive sensor to produce a second set of optical displacement data for the region. Goodness of fit (GOF) is determined of the second set of data with the first set. According to the GOF, respective GH-correction (GHC) coefficients are determined for at least one locus of the region. When measuring displacement of the at least one locus in the region relative to the tool, the respective GHC coefficient is applied to the measured displacement to reduce an error that otherwise would be present in the measured displacement due to a GH effect.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.