Canon Kabushiki Kaisha

Yasunori Furukawa

Yoshiki Maeda

Yumiko Osaki

Toru Shimizu

Yuki Yonetani

Tokuyuki Honda

The present invention provides a measurement method of measuring a surface shape of a measurement target surface including an aspherical surface by using a measurement apparatus including an optical system which guides a light from the measurement target surface to a detection unit having a detection surface, including a step of converting, into coordinates on the measurement target surface by using a coordinate conversion table, coordinates on the detection surface that indicate positions where light traveling from the measurement target surface enters the detection surface, and a step of converting, by using an angle conversion table, angle differences between angles of light reflected by a reference surface and angles of light reflected by the measurement target surface at the respective coordinates on the detection surface into angle differences at a plurality of respective coordinates on the measurement target surface that correspond to the respective coordinates on the detection surface.

Measurement method and measurement apparatus

The method includes: calculating positional and angular magnification distributions of rays reflected by a reference aspheric surface on a light-receiving sensor and on a sensor conjugate surface; measuring a first wavefront of a reference light on the sensor; and calculating a second wavefront of the reference light on the sensor based on a parameter of an optical system. The method includes: moving at least two movable elements for calibration such that a difference between rotationally symmetric components of the first and second wavefronts becomes small; measuring, after the calibration, a third wavefront of the reference light on the sensor; measuring, after the calibration, a fourth wavefront of the measurement light on the sensor; and calculating the profile of the measurement object aspheric surface by using the third and fourth wavefronts, the positional and angular magnification distributions, and the profile of the reference aspheric surface.

Aspheric surface measuring method, aspheric surface measuring apparatus, optical element producing apparatus and optical element

A surface shape measurement method that divides a surface shape of an object () into a plurality of partial regions () to obtain partial region data and that stitches the partial region data to measure the surface shape of the object, and the method includes the steps of calculating sensitivity of an error generated by a relative movement between the object and a sensor () for each of the partial regions, dividing the surface shape of the object into the plurality of partial regions to obtain the partial region data, obtaining the partial region data, calculating an amount corresponding to the error using the sensitivity, correcting the partial region data using the amount corresponding to the error, and stitching the corrected partial region data to calculate the surface shape of the object.

Surface shape measurement method, surface shape measurement apparatus, non-transitory computer-readable storage medium, optical element, and method of manufacturing optical element

The method includes: measuring a first wavefront of a reference light on a sensor by using the sensor; calculating a second wavefront of the reference light on the sensor by using a parameter of an optical system; changing an optical system parameter in calculation such that a difference between rotationally symmetric components of the first and second wavefronts becomes smaller; calculating, by using the changed parameter, a magnification distribution of rays of the reference light between on the sensor and on a sensor conjugate surface; measuring a first ray angle distribution of the reference light by using the sensor, and measuring a second ray angle distribution of a measurement light by using the light-receiving sensor. The method calculates the profile of the measurement object aspheric surface by using the profile of the reference aspheric surface, the first and second ray angle distributions and the magnification distribution.

An interferometer that measures a shape of a surface of an inspection object includes an interference optical system that splits light from a light source into inspection light and reference light and causes the inspection light reflected by the surface of the inspection object and the reference light to interfere with each other, and a photoelectric conversion element that detects interference fringes produced by interference between the inspection light and the reference light. The interference optical system includes a first optical element that transmits and reflects the inspection light, a second optical element that reflects the inspection light, and a moving unit configured to move the second optical element. The inspection light passes through the first optical element, is reflected by the second optical element, is reflected by the first optical element, and is then incident on the surface of the inspection object.

Interferometer for aspherical or spherical surface measurements

A measurement apparatus which measures spatial coherence in an illuminated plane illuminated by an illumination system, comprises a measurement mask which has at least three pinholes and is arranged on the illuminated plane, a detector configured to detect an interference pattern formed by lights from the at least three pinholes, and a calculator configured to calculate the spatial coherence in the illuminated plane based on a Fourier spectrum obtained by Fourier-transforming the interference pattern detected by the detector.

Measurement apparatus and exposure apparatus

A measurement apparatus which measures a wavefront aberration of an optical system to be measured, the apparatus comprises a detection unit configured to detect an interference pattern formed by light having passed through a mask inserted on an object plane of the optical system to be measured, and a mask inserted on an image plane of the optical system to be measured.

Growing community of inventors

Utsunomiya, Japan

Yasunori Furukawa