System and method for illuminating a specimen with uniform angular and spatial distribution
US7654715B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 9, 2007 |
| Grant date | Feb 2, 2010 |
| Priority date | — |
| Expiry date | Jan 8, 2028 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B6/4298
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A system for illuminating a specimen are disclosed herein. In general, the system may include an illumination source configured to generate light with an uneven distribution at a pupil plane and field stop of the system, a lightpipe coupled for redistributing the light across the pupil plane and field stop, and at least one optical element configured to direct the redistributed light onto a specimen. The lightpipe may generally include a cone-shaped portion and a rectangular-shaped portion. The cone-shaped portion is configured for modifying an angular distribution of the generated light, so that the redistributed light is uniformly distributed across the pupil plane of the system. The rectangular-shaped portion is formed contiguous with the cone-shaped portion and configured for modifying a spatial distribution of the generated light, so that the redistributed light is uniformly distributed across a field stop of the system. A method for illuminating a specimen and a system for inspecting a specimen are also disclosed herein.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.