Film thickness mapping using interferometric spectral imaging
US5856871A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 21, 1997 |
| Grant date | Jan 5, 1999 |
| Priority date | — |
| Expiry date | Jan 21, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01J2003/2866
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method of determining the thickness map of a film (14) overlying a substrate (14). This method includes illuminating (10) the film simultaneously from different angles and analyzing spectral intensity of the radiation reflected by each point on the film (14). The analysis is effected by collecting reflected radiation from the film (14), passing the radiation through an interferometer (16) which outputs modulated radiation corresponding to a predetermined set of linear combinations of the spectral intensity of the radiation emitted from each pixel, simultaneously and separately scanning optical path differences generated in the interferometer (16) for each pixel, focusing the radiation outputted from the interferometer (16) on a detector array, and processing the output of the detector array to determine the spectral intensity of each pixel thereof to obtain a spectral intensity distribution. Finally, the method includes further processing the spectral intensity distribution to determine the spatial distribution of the thickness of the film (16).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.