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US 8,009,272 B2Granted
Method and device for image measurement, exposure apparatus, substrate for image measurement, and device manufacturing method
AssigneeCanon Kabushiki Kaisha
InventorAkinori Ohkubo
Life of this patent
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Abstract
An image measurement method is provided for measuring an image of a pattern of a mask projected with a projection optical system. The method includes the steps of detecting light transmitted through an aperture while a substrate is arranged at an image plane of the projection optical system, the substrate having a slit and the aperture having a width larger than a width of the slit; adjusting an alignment angle of the slit on the basis of a signal related to the light detected in the detecting; and measuring the image by detecting light transmitted through the slit while moving the slit, the alignment angle of which has been adjusted in the adjusting, in the image plane of the projection optical system.
Claims11
An image measurement method for measuring an image of a pattern of a mask projected with a projection optical system, the method comprising:
- detecting light transmitted through an aperture while a substrate is arranged at an image plane of the projection optical system, the substrate having a slit and the aperture;
- adjusting an alignment angle of the slit on the basis of a signal related to the light detected in the detecting;
- and
- measuring the image by detecting light transmitted through the slit while moving the slit, the alignment angle of which has been adjusted in the adjusting, in the image plane of the projection optical system,
- wherein the width of the slit is smaller than a wavelength of light for illumination of the mask,
- wherein the width of the aperture is larger than the wavelength of the light for the illumination of the mask, and
- wherein the light transmitted through the aperture and the light transmitted through the slit are detected by a photodetector array.
4 more elements
An image measurement device configured to measure an image of a pattern of a mask projected with a projection optical system, the device comprising:
- a detection unit configured to detect light transmitted through an aperture while a substrate is arranged at an image plane of the projection optical system, the substrate having a slit and the aperture;
- a signal processing unit configured to process a signal related to the light detected by the detection unit;
- and
- an alignment unit configured to adjust an alignment angle of the slit on the basis of the signal processed with the signal processing unit,
- wherein the image is measured by detecting light transmitted through the slit while moving the slit, the alignment angle of which has been adjusted by the alignment unit, in the image plane of the projection optical system,
- wherein the width of the slit is smaller than a wavelength of light for illumination of the mask,
- wherein the width of the aperture is larger than the wavelength of the light for the illumination of the mask, and
- wherein the detection unit includes a photo detector array, and the light transmitted through the aperture and the light transmitted through the slit are detected by a photodetector array.
5 more elements
An exposure apparatus configured to expose a substrate to light, the apparatus comprising:
- an illumination optical system configured to illuminate a mask with light from a light source;
- a projection optical system configured to project an image of a pattern of the mask on the substrate;
- and
- an image measurement device configured to measure the image of the pattern of the mask projected with the projection optical system, the device including,
- a detection unit configured to detect light transmitted through an aperture while the substrate is arranged at an image plane of the projection optical system, the substrate having a slit and the aperture;
- a signal processing unit configured to process a signal related to the light detected by the detection unit;
- and
- an alignment unit configured to adjust an alignment angle of the slit on the basis of the signal processed with the signal processing unit,
- wherein the image is measured by detecting light transmitted through the slit while moving the slit, the alignment angle of which has been adjusted by the alignment unit, in the image plane of the projection optical system,
- wherein the width of the slit is smaller than a wavelength of light for illumination of the mask,
- wherein the width of the aperture is larger than the wavelength of the light for the illumination of the mask,
- wherein the detection unit includes a two-dimensional a photodetector array, and the light transmitted through the aperture and the light transmitted through the slit are detected by the same two-dimensional photodetector array,
- wherein a first photodetection portion as the photodetector detects the light transmitted through the slit, and
- wherein a second photodetection portion, which is different from the first photodetection portion, detects the light transmitted through the aperture.
11 more elements
A device manufacturing method utilizing an exposure apparatus configured to expose a substrate to light, the apparatus including,
- an illumination optical system configured to illuminate a mask with light from a light source;
- a projection optical system configured to project an image of a pattern of the mask on the substrate;
- and
- an image measurement device configured to measure the image of the pattern of the mask projected with the projection optical system, the device including,
- a detection unit configured to detect light transmitted through an aperture while the substrate is arranged at an image plane of the projection optical system, the substrate having a slit and the aperture;
- a signal processing unit configured to process a signal related to the light detected by the detection unit;
- and
- an alignment unit configured to adjust an alignment angle of the slit on the basis of the signal processed with the signal processing unit,
- wherein the image is measured by detecting light transmitted through the slit while moving the slit, the alignment angle of which has been adjusted by the alignment unit, in the image plane of the projection optical system,
- wherein the width of the slit is smaller than a wavelength of light for illumination of the mask,
- wherein the width of the aperture is larger than the wavelength of the light for the illumination of the mask,
- wherein the detection unit includes a two-dimensional a photodetector array, and the light transmitted through the aperture and the light transmitted through the slit are detected by the same two-dimensional photodetector array,
- wherein a first photodetection portion as the photodetector detects the light transmitted through the slit, and
- wherein a second photodetection portion, which is different from the first photodetection portion, detects the light transmitted through the aperture;
- the method comprising:
- exposing the substrate to light by using the exposure apparatus;
- and
- developing the exposed substrate.
15 more elements
Dependencies are inferred from the claim text.