G - Physics – 01 – B
Patent
G - Physics
01
B
G01B 9/02 (2006.01) G03F 7/20 (2006.01) G03F 9/00 (2006.01) H01L 21/469 (2006.01)
Patent
CA 2338479
Coherent illumination (12) is used to illuminate a symmetrical alignment mark (18) with an image rotation interferometer (26) producing two images of the alignment mark, rotating the images 180° with respect to each other, and recombining the images interferometrically. The recombined images interfere constructively or destructively, in an amplitude and or polarization sense depending upon the method of recombination, when the alignment sensor (10) is located at the center of the alignment mark. The rotation interferometer (26) is preferably a solid glass assembly made of a plurality of prisms. A detector (28) extracts the alignment information from the image rotation interferometer (26). The resulting center of the alignment mark (18) is accurately determined. A relatively large number of different alignment mark patterns may be utilized, as long as the alignment mark patterns exhibit one hundred and eighty degree symmetry. Parallel lines, a grid pattern, or a checkerboard grating may be used. The alignment sensor (10) may be applied to a scanning photolithographic system providing sinusoidal alignment signals. The alignment system is particularly applicable to photolithography as used in semiconductor manufacturing.
Osler Hoskin & Harcourt Llp
Svg Lithography Systems Inc.
LandOfFree
Self referencing mark independent alignment sensor does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Self referencing mark independent alignment sensor, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Self referencing mark independent alignment sensor will most certainly appreciate the feedback.
Profile ID: LFCA-PAI-O-1579009