Canon Kabushiki Kaisha

Seima Kato

Chidane Ouchi

Masanobu Hasegawa

Akihiro Nakauchi

Naoki Kohara

Toshiyuki Naoi

An optical apparatus includes a first light source, a second light source, a chart, an optical system, and a light receiving system. The chart is configured to guide light emitted from the first light source to a target optical system. The optical system is configured to form a point image by using light emitted from the second light source. The light receiving system is configured to receive first light emitted from the chart via the target optical system and second light emitted from the point image via the target optical system. The first light and the second light enter different positions of the target optical system.

Optical apparatus, evaluation apparatus, evaluation method, and manufacturing method of optical system

The wavefront aberration measuring method includes measuring an intensity distribution of a measuring light transmitted through or reflected by an object to be measured, by using a light-receiving sensor, calculating a first differential wavefront which is a differential wavefront of the measuring light on the light-receiving sensor, and calculating a second differential wavefront by performing a correction process on the first differential wavefront depending on an incident angle of the measuring light to the light-receiving sensor. The method further includes calculating a wavefront aberration of the object by using the second differential wavefront.

Wavefront aberration measuring method, wavefront aberration measuring apparatus and optical element manufacturing method

A transmitted wavefront measuring method comprises the steps of emitting lightfrom a light sourceonto an object to be measuredto receive interfering light transmitted through the object and a diffraction gratingon a light receiving portiondisposed at a predetermined distance from the diffraction grating to measure an intensity distribution of the interfering light T, performing a Fourier transform of the intensity distribution to calculate a frequency distribution T, and obtaining a transmitted wavefront of the object based on a primary frequency spectrum in the frequency distribution Tto T. The step of obtaining the transmitted wavefront comprises the steps of performing an inverse Fourier transform of the primary frequency spectrum with reference to a grating frequency of the diffraction grating to calculate a complex amplitude of the interfering light T, and obtaining the transmitted wavefront based on the complex amplitude T

Transmitted wavefront measuring method, refractive-index distribution measuring method, and transmitted wavefront measuring apparatus that calculate a frequency distribution and obtain a transmitted wavefront of the object based on a primary frequency spectrum in the frequency distribution

A method includes the steps of measuring a first transmitted wavefront in a first medium having a first refractive index and a second transmitted wavefront in a second medium having a second refractive index different from the first refractive index, and obtaining a refractive index distribution projected value of the object in each orientation by removing a shape component of the object utilizing measurement results of the first transmitted wavefront and the second transmitted wavefront and each transmitted wavefront of a reference object that has the same shape as that of the object and a specific refractive index distribution and is located in one of the first medium and the second medium with the same orientation as that of the object, and calculating a three-dimensional refractive index distribution of the object based on a plurality of refractive index distribution projected values corresponding to the plurality of orientations.

Refractive index distribution measuring method and refractive index distribution measuring apparatus

A Talbot interferometer includes a diffraction grating, an image pickup device, a moving unit configured to move at least one of the diffraction grating and the image pickup device in an optical axis direction of the test object, and a computer configured to adjust a position of the at least one of the diffraction grating and the image pickup device using the moving unit so that a Talbot condition can be met, based on a spatial frequency spectrum obtained from a plurality of interference fringes captured by the image pickup device while moving the at least one of the diffraction grating and the image pickup device using the moving unit.

Talbot interferometer, its adjustment method, and measurement method

The measuring method includes a step of causing reference light to enter an object placed in a first medium to measure a first transmitted wavefront, a step of causing the reference light to enter the object placed in a second medium to measure a second transmitted wavefront, a step of measuring first and second placement positions where the object is placed in the first and second media, and a calculating step of calculating an internal refractive index distribution of the object by using measurement results of the first and second transmitted wavefronts. The calculating step calculates the internal refractive index distribution from which a shape component of the object is removed by using the measurement results of the first and second transmitted wavefronts, and first and second reference transmitted wavefronts of a reference object to be placed at positions identical to the first and second placement positions.

Refractive index distribution measuring method and apparatus using position measurement and a reference object

The method measures first transmitted wavefronts and second transmitted wavefronts by respectively causing reference light to enter an object placed in plural placement states in a first medium and a second medium, calculates an aberration sensitivity with respect to changes of the placement state of the object, and calculates an alignment error of the object in each placement state by using the aberration sensitivity and the first and second transmitted wavefronts measured in each placement state. The method further calculates first and second reference transmitted wavefronts respectively acquirable when causing the reference light to enter the reference object placed in placement states including the alignment errors in the first medium and the second medium, and calculates a refractive index distribution of the object which a shape component thereof is removed, by using the first and second transmitted wavefronts and the first and second reference transmitted wavefronts.

Refractive index distribution measuring method and apparatus, and method of producing optical element thereof, that use multiple transmission wavefronts of a test object immersed in at least one medium having a different refractive index from that of the test object and multiple reference transmission wavefronts of a reference object having known shape and refractive index distribution

A refractive index distribution measurement method includes the steps of measuring a first transmission wavefront of a test object by introducing reference light to the test object immersed in a first medium having a first refractive index lower than that of the test object by 0.01 or more, measuring a second transmission wavefront of the test object by introducing the reference light to the test object immersed in a second medium having a second refractive index lower than that of the test object by 0.01 or more and different from the first refractive index, and obtaining a refractive index distribution of the test object based on a measurement result of the first transmission wavefront and a measurement result of the second transmission wavefront.

Refractive index distribution measurement method and apparatus that measure transmission wavefronts of a test object immersed in different media having refractive index lower than that of the test object

A wavefront aberration measuring device includes a mask placed in an object plane of a to-be-tested optical system and having a pattern including a pinhole producing a spherical wave and adjoining diffraction gratings each ruled with lines oriented in a direction different from the other; an illumination optical system that illuminates an area of the mask with light emitted from a light source; a light splitter that splits the light from the pattern transmitted through the to-be-tested optical system; an image pickup unit that takes an image of interference fringes produced by the split light, the image being used in measuring wavefront aberration of the to-be-tested optical system; a detector that detects respective light quantities of respective diffracted beams from the respective illuminated diffraction gratings; and a control unit that controls alignment of the illuminated area of the mask and the pattern in accordance with a detection result.

Wavefront aberration measuring method, mask, wavefront aberration measuring device, exposure apparatus, and device manufacturing method

A measuring apparatus includes a pinhole mask, located on an object plane of an optical system to be measured, and having a plurality of pinholes for generating a spherical wave from a measuring light beam, and a diffraction grating for splitting the measuring light beam that has passed the pinhole mask and the optical system, in which Lg=m&#xb7;Pg/&#x3bb; is met, where Pg is a grating pitch of the diffraction grating, &#x3bb; is a wavelength of the measuring light beam, m is an integer other than zero, and Lg is a distance between the diffraction grating and an image plane of the optical system. The measuring apparatus detects an interferogram formed by interference between a plurality of the measuring light beams split by the diffraction grating. The plurality of measuring light beams includes an aberration of the optical system.

Measuring apparatus, exposure apparatus and method, and device manufacturing method

A measurement apparatus includes a first mask that is arranged on an object plane of a target optical system, and has a window that transmits measurement light, a second mask that has a reflection surface for reducing coherence of the measurement light, and a diffraction grating configured to split the measurement light that has been reflected on the second mask, has passed the first mask and the target optical system, wherein a distance Lg between the diffraction grating and an image plane of the target optical system satisfies Lg=m&#xb7;Pg/&#x3bb; where Pg is a grating pitch of the diffraction grating, &#x3bb; is a wavelength of the measurement light, and m is an integer except for 0.

Measurement apparatus, exposure apparatus having the same, and device manufacturing method

The invention provides a measurement apparatus which measures a wavefront aberration of an optical system to be measured, the apparatus includes a measurement mask which is inserted on an object plane of the optical system to be measured, and includes a plurality of reflection units configured to generate spherical waves by reflecting light, the measurement mask including a reflection layer configured to reflect the light, a first layer which is stacked on the reflection layer, has a plurality of openings, and is made of a first substance, and a second layer which is stacked on the first layer, has a window configured to expose a region in which the plurality of openings are arrayed, and is made of a second substance different from the first substance, wherein the plurality of reflection units are formed by portions of the reflection layer, which are exposed through the plurality of openings.

Measurement apparatus, exposure apparatus, and device fabrication method

Disclosed is a method of analyzing an interference fringe, with which method the optical characteristics of an optical system to be examined can be analyzed very precisely. In one preferred form of the invention, the analyzing method includes a step of detecting information related to a first interference fringe produced by interference of two light fluxes, a step of detecting information related to a second interference fringe produced while changing a phase of one of the two light fluxes by &#x3c0; as multiplied by an odd number (e.g., 1&#x3c0;, 3&#x3c0;, . . . ), and a step of detecting averaged information of phase information of the two interference fringes, on the basis of the detected information of the first and second interference fringes and by use of Fourier transform.

Method and apparatus for analyzing interference fringe

A measuring apparatus for measuring the optical properties of an optical system including a mask with a slit and a window, upon which different light beams are focused to derive an interference pattern. The interference pattern can be used to obtain optical properties of the optical system.

Apparatus for measuring optical properties of tested optical system using interference

A measuring method for measuring an interference fringe includes the steps of generating a reference wave as a result of transmission through a slit or pinhole in a mask of a portion of light that has passed a target optical system, generating the interference fringe between the reference wave and a wave of another portion of light that has passed the target optical system and contains aberration information of the target optical system, determining whether contrast of the interference fringe is higher than a predetermined threshold, and exchanging the pinhole or the slit when the contrast is below the predetermined threshold.

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Utsunomiya, Japan

Seima Kato