PATENTSCOPE will be unavailable a few hours for maintenance reason on Tuesday 19.11.2019 at 4:00 PM CET
Search International and National Patent Collections
Some content of this application is unavailable at the moment.
If this situation persists, please contact us atFeedback&Contact
1. (WO2007005340) BEAM DELIVERY SYSTEM FOR LASER DARK-FIELD ILLUMINATION IN A CATADIOPTRIC OPTICAL SYSTEM
Note: Text based on automatic Optical Character Recognition processes. Please use the PDF version for legal matters

WHAT IS CLAIMED IS:

1. An apparatus for inspecting a specimen, comprising:

a primary illumination source;

a catadioptric objective exhibiting a central obscuration that accepts light energy received from the primary illumination source and delivers light energy at angles substantially greater than normal, wherein substantially greater than normal represents angles substantially greater than approximately zero degrees, toward the specimen; and

an optical device positioned within the central obscuration resulting from the catadioptric objective for receiving further illumination from a secondary illumination source and diverting the further illumination at near normal incidence to the specimen.

2. The apparatus of claim 1, further comprising a detector arrangement sensitive to a wavelength of illumination from the secondary illumination source.

3. The apparatus of claim 1 where the central obscuration is less than approximately 15% of a pupil diameter of the catadioptric objective.

4. The apparatus of claim 1 where the optical device comprises a prism.

5. The apparatus of claim 1 where the optical device comprises a reflective surface.

6. The apparatus of claim 2 where the detector arrangement comprises a plurality of detectors.

7. The apparatus of claim 1 where the primary illumination source comprises an arc lamp.

8. The apparatus of claim 1 where the secondary illumination source wavelength comprises at least one wavelength from a group comprising 193, 198,

213, 244, 257, 266, 363.8, 354, 351, 355, 325, and 532nm.

9. The apparatus of claim 2 wherein the detector arrangement comprises at least one Time Delay and Integration sensor.

10. The apparatus of claim 1, further comprising an optical Fourier filter aperture located at a pupil plane of the apparatus, and wherein the optical Fourier

5 filter aperture attenuates repeating pattern signals received from the specimen.

11. The apparatus of claim 10 where the optical Fourier filter aperture comprises a spectrally narrow-band dielectric thin film pattern, wherein the spectrally narrow-band dielectric thin film pattern blocks components of the further illumination from the secondary illumination source while substantially transmitting the
0 illumination from the primary illumination source.

12. An apparatus located within a central obscuration of an optical inspection system comprising an objective, a primary illumination source and a secondary illumination source, wherein the primary illumination source provides illumination through the objective and at an angle relatively larger than normal to a S surface of a specimen, and further wherein the secondary illumination source provides further illumination substantially normal to the surface of the specimen, the apparatus comprising:

a surface positioned within the central obscuration to direct the further illumination to the surface of the specimen at normal incidence to the surface; and

0 a fastening mechanism positioned predominantly within the obscuration, the fastening mechanism employed to fixedly position the surface during inspection.

13. The apparatus of claim 12 where the surface and fastening mechanism allow a wavelength between approximately 193 nm and 400 nm to be transmitted to the surface.

5 14. The apparatus of claim 12 where the surface comprises a reflective surface.

15. The apparatus of claim 12 where the surface forms part of a prism.

16. The apparatus of claim 12 where the surface is a prism formed within a mechanical support component.

17. The apparatus of claim 12 where the fastening mechanism comprises an epoxy.

18. The apparatus of claim 12 where the fastening mechanism comprises optical contacting.

19. A method of inspecting a specimen, comprising:

illuminating a surface of the specimen at a variety of angles using a primary illumination source;

illuminating the surface using a secondary illumination source, said illuminating by the secondary illumination source occurring at a substantially normal angle of incidence; and

imaging all reflected, scattered, and diffracted light energy received from the surface onto a detector.

20. The method of claim 19, wherein the primary illumination source is broad-band and the secondary illumination source is narrow-band.

21. The method of claim 19 wherein illuminating the surface using the secondary illumination source comprises directing light energy from the secondary illumination source to the surface using a light deflecting device positioned within a central obscuration of light energy from the primary illuminating source.

22. The method of claim 19, wherein the illuminating by the primary illumination source occurs contemporaneously with the illuminating by the secondary illumination source.

23. The method of claim 19, wherein the illuminating by the primary illumination source occurs at a time different from the illuminating by the secondary illumination source.