Method for measuring thickness
US8279447B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 1, 2008 |
| Grant date | Oct 2, 2012 |
| Priority date | — |
| Expiry date | Dec 26, 2028 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01B11/0675
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Disclosed is a method for measuring a thickness of a subjecting layer attached on a base layer by means of an interferometer, which includes the steps of: obtaining a correlation equation of a phase difference with respect to thicknesses of sample layers, the thicknesses being different from each other, the sample layers being made from a material substantially equal to a material of the subjecting layer; obtaining a first interference signal with respect to an optical axial direction incident to the base layer at a boundary surface between an air layer and the base layer; obtaining a second interference signal with respect to the optical axial direction at a boundary surface between the subjecting layer and the base layer; obtaining a phase difference between a phase of the first interference signal and a phase of the second interference signal at respective heights substantially equal to each other with respect to the optical axial direction; and determining a thickness of the subjecting layer by inserting the phase difference into the correlation equation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.