초록 ▼

Disclosed is a method and apparatus for detecting a relative positional deviation between first and second objects. In one preferred form of the invention, the detecting method includes the steps of (i) providing the first and second objects with diffraction gratings, respectively, each having a gra

Disclosed is a method and apparatus for detecting a relative positional deviation between first and second objects. In one preferred form of the invention, the detecting method includes the steps of (i) providing the first and second objects with diffraction gratings, respectively, each having a grating pitch larger than a wavelength of a light source used, (ii) placing the first and second objects so that a dielectric material layer having a thickness smaller than the wavelength of the light source used is interposed between the first and second objects, and so that the diffraction gratings of the first and second objects are opposed to each other, (iii) projecting light from the light source onto the diffraction gratings of the first and second objects, and (iv) detecting the relative positional deviation between the first and second objects on the basis of diffraction light projected from the diffraction gratings to a space.

대표청구항 ▼

What is claimed is: 1. A method of detecting a relative positional deviation between first and second objects, said method comprising the steps of: providing the first and second objects with diffraction gratings, respectively, each having a grating pitch larger than a wavelength of a light source

What is claimed is: 1. A method of detecting a relative positional deviation between first and second objects, said method comprising the steps of: providing the first and second objects with diffraction gratings, respectively, each having a grating pitch larger than a wavelength of a light source used; placing the first and second objects so that a dielectric material layer having a thickness smaller than the wavelength of the light source used is interposed between the first and second objects, and so that the diffraction gratings of the first and second objects are opposed to each other; projecting light from the light source onto the diffraction gratings of the first and second objects; and detecting the relative positional deviation between the first and second objects on the basis of diffraction light projected from the diffraction gratings to a space. 2. A method according to claim 1, wherein the first and second objects are provided with plural pairs of diffraction gratings, the diffraction gratings in each pair being disposed opposed to each other, and wherein light from the light source is incident on the plural pairs of diffraction gratings and diffraction light projected from the plural pairs of diffraction gratings to the space is detected. 3. A method according to claim 1, wherein each of the diffraction gratings is a two-dimensional diffraction grating. 4. A method according to claim 1, wherein one of the first and second objects is a photomask while the other is a substrate to be exposed, and wherein the dielectric material layer is a photosensitive material layer. 5. A method according to claim 1, wherein one of the first and second objects is an optical nanoimprint mold while the other is a substrate to be processed, and wherein the dielectric material layer is a curing resin layer. 6. An apparatus for detecting a relative positional deviation between first and second objects, said apparatus comprising: a light source having a predetermined wavelength; diffraction gratings provided on the first and second objects, respectively, each having a grating pitch larger than the wavelength of the light source used, the first and second objects being disposed so that the diffraction gratings of the first and second objects are opposed to each other; a dielectric material layer disposed between the first and second objects and having a thickness smaller than the wavelength of the light source; and detecting means for detecting diffraction light produced in response to projection of light from the light source onto the diffraction gratings of the first and second objects and for detecting the relative positional deviation between the first and second objects on the basis of diffraction light projected from the diffraction gratings to a space. 7. An apparatus according to claim 6, wherein the first and second objects are provided with plural pairs of diffraction gratings, the diffraction gratings in each pair being disposed opposed to each other, and wherein light from the light source is incident on the plural pairs of diffraction gratings and diffraction light projected from the plural pairs of diffraction gratings to the space is detected by said detecting means. 8. An apparatus according to claim 6, wherein each of the diffraction gratings is a two-dimensional diffraction grating. 9. An apparatus according to claim 6, wherein one of the first and second objects is a photomask while the other is a substrate to be exposed, and wherein the dielectric material layer is a photosensitive material layer. 10. An apparatus according to claim 6, wherein one of the first and second objects is an optical nanoimprint mold while the other is a substrate to be processed, and wherein the dielectric material layer is a curing resin layer.