Method and device for measuring the thickness of opaque and transparent films
US5812261A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 15, 1997 |
| Grant date | Sep 22, 1998 |
| Priority date | — |
| Expiry date | Jan 15, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2291/0423
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method for determining the thickness of a thin sample is described. The method includes the step of exciting time-dependent acoustic waveguide modes in the sample with an excitation radiation field. The acoustic waveguide modes are detected by diffracting probe radiation off a ripple morphology induced on the sample's surface by the acoustic waveguide modes. The diffracted probe radiation is then analyzed to measure phase velocities or frequencies of the acoustic waveguide modes. A thickness of the thin sample is determined by comparing the measured phase velocities or frequencies to the phase velocities or frequencies calculated from a mathematical model.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.