Method and assembly for determining the thickness of a layer in a sample stack
US9587930B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Jul 29, 2016 |
| Grant date | Mar 7, 2017 |
| Priority date | — |
| Expiry date | Jul 29, 2036 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N21/211
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method for determining the thickness of a layer in a sample stack of at least two layers with an assembly comprising a light source for illuminating a stack of layers and a detector for detecting light reflected by the stack of layers in a defined first wavelength range, the method comprises a first step of obtaining a calibration curve by the calibrating steps of providing two or more reference stacks of layers, where each layer of the reference stacks has a known thickness, the same material as the sample stack and the layers occur in the same order as in the sample stack; illuminating the reference stacks with light from the light source; and detecting the intensity of light reflected by the reference stacks with the detector in the first wavelength range. Further steps of the method comprise illuminating the sample stack of layers with light from the light source; detecting the intensity of the light reflected by the sample stack of layers with the detector in the first wavelength range; and determining the thickness of the layer comprised in the sample stack of layers from the intensity detected by the detector by means of the calibration curve. The method is characterized i…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.