Method for measuring thickness variations in a layer of a multilayer semiconductor structure
US9759546B2 · kind B2 · utility
Assignees
Inventors
Key dates
| Filing date | Sep 19, 2013 |
| Grant date | Sep 12, 2017 |
| Priority date | — |
| Expiry date | Jan 29, 2034 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L22/12
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The invention relates to a method for measuring thickness variations in a layer of a multilayer semiconductor structure, characterized in that it comprises: acquiring, via an image acquisition system, at least one image of the surface of the structure, the image being obtained by reflecting an almost monochromatic light flux from the surface of the structure; and processing the at least one acquired image in order to determine, from variations in the intensity of the light reflected from the surface, variations in the thickness of the layer to be measured, and in that the wavelength of the almost monochromatic light flux is chosen to correspond to a minimum of the sensitivity of the reflectivity of a layer of the structure other than the layer the thickness variations of which must be measured, the sensitivity of the reflectivity of a layer being equal to the ratio of: the difference between the reflectivities of two multilayer structures for which the layer in question has a given thickness difference; to the given thickness difference, the thicknesses of the other layers being for their part identical in the two multilayer structures. The invention also relates to a measuring sys…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.