Boots – shoes – and leggings
Patent
1984-04-24
1987-10-27
Gruber, Felix D.
Boots, shoes, and leggings
356354, 356356, 356358, G01B 902, G06F 1560
Patent
active
047034343
ABSTRACT:
The present invention is directed to new and improved apparatus for measuring overlay error between a wafer pattern and a mask pattern projected onto the wafer pattern by a lithographic exposure instrument, which includes a grating mask; a grating wafer having reflective lines alternating with non-reflective spaces patterned like the mask pattern; the lithographic instrument having projection optics mounted to project an image of the mask on the wafer, and a mechanism for moving the grating mask and grating wafer relative to the projection optics; the grating on the wafer being offset from the grating on the mask forming Moire fringes corresponding to the overlay error between the wafer pattern and a mask pattern projected onto the wafer; a photodiode array wherein each photodiode corresponds to a pixel on the grating wafer; viewing optics mounted to project the Moire fringes onto the photodiode.
REFERENCES:
patent: 3928094 (1975-12-01), Angell
patent: 3955072 (1976-05-01), Johannsmuier et al.
patent: 4167337 (1979-09-01), Jaerisch et al.
patent: 4172664 (1979-10-01), Charsky et al.
patent: 4330213 (1982-05-01), Kleinknacht et al.
patent: 4408884 (1983-10-01), Kleinknacht et al.
patent: 4445776 (1984-05-01), Hyatt
patent: 4493555 (1985-01-01), Reynolds
patent: 4515481 (1985-05-01), Yamada et al.
patent: 4577968 (1986-03-01), Makosch
patent: 4578590 (1986-03-01), Wu
Grimes Edwin T.
Gruber Felix D.
Laibowitz Danielle B.
Masselle Francis L.
Murphy Thomas P.
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