Flat spectrum illumination source for optical metrology
US7154607B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 3, 2003 |
| Grant date | Dec 26, 2006 |
| Priority date | — |
| Expiry date | Nov 18, 2024 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2201/0826
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A flat spectrum illumination source for use in optical metrology systems includes a first light source generating a visible light beam and a second light source generating an ultraviolet light beam. The illumination source also includes an auxiliary light source generating a light beam at wavelengths between the visible light beam and the ultraviolet light beam. The three light beams are combined to provide a broadband probe beam that has substantially even illumination levels across a broad range of wavelengths. Alternately, the illumination source may be fabricated as an array of light emitting diodes selected to cover a range of separate wavelengths. The outputs of the LED array are combined to produce the broadband probe beam.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.