Optics: measuring and testing – By alignment in lateral direction – With light detector
Patent
1988-07-29
1989-10-03
Evans, F. L.
Optics: measuring and testing
By alignment in lateral direction
With light detector
350523, 356237, 356401, 356446, G01B 1100, G01N 2188, G01N 2147
Patent
active
048712574
ABSTRACT:
In a detection optical apparatus for an object having an actual circuit pattern that diffracts an incident light and has an alignment pattern, an illumination device having a first aperture for controlling the beam of light, the illumination device adapted to effect a dark-field illumination to the object, and an imaging optical system for forming the image of the object. The imaging optical system has a second aperture located at a position optically conjugate with the first aperture by way of the object, the first and second apertures being not overlapped when the image of the first aperture is formed on the second aperture. The second aperture has such a light blocking area that blocks diffraction light produced when the beam of light passed through the light-transmitting area of the first aperture is incident on the actual circuit pattern. Also, an optical inspection apparatus for optically inspecting articles such as photomasks or wafers, having patterns each formed by linear pattern elements having a certain directional characteristic with respect to plural directions, is disclosed. Among the linear pattern elements, at least those extending in one direction are extracted out and observed in a dark field, and any faults of the pattern such as breaks or the like and any foreign particles adhered to the pattern are detected on the basis of a reduced amount of information as compared with the information concerning the whole pattern.
REFERENCES:
patent: 3850527 (1974-11-01), Winthrop et al.
patent: 3879131 (1975-04-01), Cuthbert et al.
patent: 3930713 (1976-01-01), Stankewitz
patent: 4062623 (1977-12-01), Suzuki et al.
patent: 4202627 (1980-05-01), Suzki et al.
patent: 4251129 (1981-02-01), Suzki et al.
patent: 4390279 (1983-06-01), Suwa
patent: 4423959 (1984-01-01), Nakazawa et al.
patent: 4595289 (1986-06-01), Feldman et al.
patent: 4601577 (1986-07-01), Gotou et al.
Khoury, IBM Technical Disclosure Bulletin, vol. 17, No. 10, Mar. 1975, p. 2895.
Kohno Michio
Suzuki Akiyoshi
Canon Kabushiki Kaisha
Evans F. L.
LandOfFree
Optical apparatus for observing patterned article does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Optical apparatus for observing patterned article, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Optical apparatus for observing patterned article will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-661059