Alignment apparatus
AssigneeNikon Corporation
InventorsKazuya Ota, Hiroki Okamoto
Life of this patent
Estimating the term…
Abstract
In an alignment apparatus for irradiating detection laser beams LB1 and LB2 to an alignment mark and detecting a position of a wafer 1 by using a light produced from the alignment mark, a width d of a recess 2b of the alignment mark along an alignment direction is set to be smaller than a length (.lambda.+c) which is larger than a wavelength A of the laser beams LB1 and LB2 by a predetermined amount c, to thereby provide an alignment apparatus in which it is hard to create a detection error even if the alignment mark is asymmetric.
Claims11
An alignment apparatus comprising:
- an alignment mark including projections and recesses formed on an article under test along an alignment direction;
- an illumination optical system for irradiating a position detection light to said alignment mark;
- a width of the recess of said alignment mark along the alignment direction being selected to be smaller than three times of a wavelength of the position detection light;
- and
- a detection optical system for detecting a light produced from said alignment mark by the irradiation of the light.
An alignment apparatus comprising:
- an alignment mark having projections and recesses arranged iteratively on an article along an alignment direction;
- an illumination optical system for irradiating linearly polarized light for position detection to said alignment mark;
- a width of the recess of said alignment mark along the alignment direction being selected to be smaller than three times of a wavelength of said light for position detection;
- and
- a photosensitive optical system for sensing the light produced from said alignment mark by the irradiation of the light.
An alignment apparatus comprising:
- an alignment mark having projections and recesses arranged iteratively on an article along an alignment direction;
- an illumination optical system for irradiating linearly polarized light for position detection to said alignment mark, said linearly polarized light for position detection being so controlled that a direction of an electric vector on said alignment mark is orthogonal to said alignment direction;
- and
- a photosensitive optical system for sensing light produced from said alignment mark by the irradiation of the light.
An alignment apparatus comprising:
- an alignment mark having projections and recesses arranged iteratively on an article along an alignment direction;
- an illumination optical system for irradiating linearly polarized light for position detection to said alignment mark, said linearly polarized light for position detection being so controlled that a direction of an electric vector on said alignment mark is coincident with said alignment direction;
- and
- a photosensitive optical system for sensing light produced from said alignment mark by the irradiation of the light.
An alignment apparatus comprising:
- an alignment mark having projections and recesses arranged iteratively on an article along an alignment direction;
- an illumination optical system for irradiating linearly polarized light for position detection to said alignment mark, said linearly polarized light for position detection being so controlled that a direction of an electric vector on said alignment mark is orthogonal to said alignment direction;
- and
- said illumination optical system including an adjusting device for changing direction of the linear polarization on said alignment mark between a first direction in which an electric vector on said alignment mark is orthogonal to said alignment direction and a second direction in which the electric vector on said alignment mark is coincident with said alignment direction;
- and
- a photosensitive optical system for sensing light produced from said alignment mark by the irradiation of the light.
Dependencies are inferred from the claim text.