387 results about "Wave aberration" patented technology

The invention relates to a projection objective lens wave aberration detection device and method. Light emitted by a light source is uniformly radiated on a projection objective lens object plane, a scatter plate and a needle hole are installed on a masking stage, the needle hole is arranged on an object plane of a projection objective lens, the field of view is selected through the movement of the masking stage, a shearing grating is arranged on an image plane of the projection objective lens, the shearing grating is installed on a wafer stage together with a detector, the phase shifting function is realized through the transverse precise movement of the grating by the wafer stage, and simultaneously each frame of a shearing interference figure in the phase shifting process is recorded by utilizing the detector. Two-dimensional shearing is realized by utilizing the two-dimensional grating, the phase shifting function is integrated into the shearing interference instrument, and the high-precise measurement of the projection objective lens wave aberration is realized by adopting the characteristics of the phase space vector.

The invention discloses an on-line detection device with the function of calibrating a systematic error for wave aberration of a projection objective of a photoetching machine, belonging to the fieldof optical detection. The device comprises an object space mask plate with circular holes, a phase-shifting device, a photoelectric sensor, a memorizer, a controller, an arithmetic unit, a beam splitting device and an image space mask plate, wherein the beam splitting device comprises two binary diffraction gratings: a first grating and a second grating; and the image space mask plate comprises awindow and a first circular hole and a second circular hole with equal diameters. The second grating of the beam splitting device and the second circular hole of the image space mask plate are used aselements for calibrating the systematic error, and the systematic error of the device is calibrated according to the orthogonal property and the odd-even symmetrical property of the Zernike multinomial in a unit circle. The device of the invention is integrated on a masking workpiece platform and a silicon slice workpiece platform of the photoetching machine, and compared with the prior art, thedevice can calibrate the systematic measurement error introduced by a measuring device, thereby increasing the accuracy of measurement.

The invention discloses a wave aberration detection device of an objective lens imaging system. The wave aberration detection device comprises a light source, a collimating mirror, a spectroscope, a focusing mirror, a standard spherical reflector, a data processing unit, a wave-front sensor, a first accurate adjustment table and a second accurate adjustment table, wherein the collimating mirror, the spectroscope, the focusing mirror and the standard spherical reflector are sequentially placed in the light emitting direction of the light source, and the wave-front sensor, the first accurate adjustment table and the second accurate adjustment table are connected with the data processing unit. In the wave aberration detection device, the measurement processes and the system error calibration process are switched by changing the position of the standard spherical reflector 5; in the two measurement processes, the standard spherical reflector 5 has the same adjustment accuracy, and therefore the calibration, measurement and correction of device and system errors can be effectively completed, and the wave aberration measurement accuracy is improved. No high-precision standard light source is needed, and cost is reduced; A system error calibration method of the wave aberration detection device is simple and compact in structure and has the advantages of being easy to obtain and the like, and the wave aberration detection of the objective lens imaging system to be detected can be completed through the simple system.

The invention relates to an on-line detection method for detecting the wave aberration of a projection objective of a photoetching machine. The on-line detection, revising, and controlling are done to the wave aberration of the projection objective by integrating an interferometer device on the photoetching machine. The interferometer device is a point-diffraction interferometer or a slit-diffraction interferometer and is provided with two measuring modules: a PSI measuring module and an FTM measuring module. The PSI measuring module adopts phase shifting interferometry with high measuring precision and is mainly used to detect the error calibration in an interferometer device system; the FIM measuring module adopts fourier transform method to treat with interference fringes with high measuring speed, and is mainly used to on-line detect and control the wave aberration of the projection objective. The method improves the measuring precision without reducing the measuring speed, and improves the measuring precision and reproducibility of the interferometer device by adopting a higher quality spherical reference wave to calibrate the systematic error caused by each component of the interferometer device without reducing the contrast ratio of the interference fringes.

An improved wavefront sensor is provided that enhances the initial focus and precision of imaged spots used to determine the monochromatic wave aberrations of the eye. The wavefront sensor includes an adjustment camera that is independent of a lenslet camera. A laser in a lower power mode is projected onto the retina of the eye and is brought into more precise or sharp focus by a control system employing data from the adjustment camera, which aids in focusing the imaged spots. “Trombone”-type optics are used to adjust the focus of the light projected onto the retina and the imaged spots onto a sensor. The laser has a higher power mode used when acquiring data of the imaged spots from the sensor.

The invention discloses a photoetching machine projection objective wave aberration on-line detector and a method. A diffuser is integrated on an object space mask plate which is arranged on the object plane of a projection objective, fixed, supported and driven by an object space work piece table in the photoetching machine; an image space mask plate is arranged on the image plane of the projection objective, supported and driven by an image plane work piece table. A collimator objective is arranged after the image surface of the projection objective; and the focal plane of the object space of the collimator objective is coincided with the image plane of the projection objective. Shearing mechanism is arranged between the projection objective and a photoelectric detector. The invention can realize the continuous tunableness of the shear ratio and increases the measuring sensitivity and measuring accuracy; secondly, a square hole is used for expanding the light source, thus increasing the utilization factor of the light intensity of the exposure light source, the measuring speed and measuring accuracy; and finally, the system error self-calibration technology can rapidly obtain the wave aberration of the projection objective with high precision.

An optical system wave aberration calibration apparatus and a calibration method of using the apparatus to test an error relate to the optical measurement technology field. The current optical system can not evaluate whether the test error satisfies a detection precision requirement before detecting an optical element and the current optical system can not select an appropriate phase shifting algorithm to process collected data. The above problems can be solved by using the invention. The method comprises the following steps: a light splitting system emits two beams of common-optical-path orthogonal-line polarized lights and after being emitted by a polarization splitting prism, the polarized lights are coupled to a reference fiber through a coupling lens; two spherical waves diffracted by the reference fiber perform interference and an interferogram can be acquired; a photoelectric detector is used to collect the interferogram and to transmit to a computer; piezoelectric ceramics areused to carry out phase shifting and the photoelectric detector collects the interferogram several times; a thirteen step phase shifting algorithm is used to carry out data processing analysis so as to obtain the test error. By using the invention, ultrahigh precision testing of the optical system wave aberration can be realized.

The low-order aberration leading to better visual acuity is calculated from the results of measurement of an eye characteristic by an eye characteristic measuring instrument that can measure up to the high-order aberration, and data on a correction factor is collected, thereby obtaining a result more approximate to the subjective value. According to at least measurement data representing the wave aberration of the eye being examined (S401, S403), an image data creating unit creates optotype retina image data by conducting simulation of the visual acuity of an optotype (S405), considering the correction factor for refraction correction. A correction factor setting unit sets a correction factor to be given to the image data creating unit (S417). A judging unit judges from the correction opotype retina image data corrected by the correction factor whether or not an adequate correction factor is set (S407 to S421). The correction factor setting unit sets a correction factor on the basis of the results of judgment by the judging unit, and changes the correction factor until the judging unit judge that the correction factor is adequate.

The invention discloses a real-time measuring device for wave aberration, which comprises a light source, a beam splitter, a lighting system, an object surface pinhole, an objective lens system, a shearing grating, a two-dimensional array photosensitive element, an energy sensor, and a synchronous control and comparison part, wherein the beam splitter splits light emitted by the light source into a first light beam and a second light beam; the lighting system receives the first light beam emitted by the beam splitter; the object surface pinhole receives light emitted by the lighting system to form a probe light source; the objective lens system is used for imaging the pinhole; the shearing grating is positioned on the image surface of the objective lens system and diffracts probe light emitted by the pinhole; the probing surface of the two-dimensional array photosensitive element receives shearing interference fringes generated by the shearing grating and is conjugate with the pupilplane of an objective lens; the energy sensor receives the second light beam emitted by the beam splitter; and the synchronous control and comparison part is connected with the light source, the energy sensor and the two-dimensional array photosensitive element through signal wires. During measurement, the synchronous control and comparison part controls the energy sensor and the two-dimensional array photosensitive element to perform synchronous optical energy integral at the same time interval, and a measuring result of the two-dimensional array photosensitive element is calibrated by a measuring result of the energy sensor.

The invention relates to a method for detecting the surface shape of a large-aperture telescope by using phase diversity phase retrieval. The method comprises the following steps of: representing a 2-bit variable by using a 1-bit variable in order to representing an imaging relation of an optical system; expanding a wave aberration into a series, solving a transfer function by using self-correlation operation of a pupil function and changing a Zernike coefficient so as to obtain different transfer function calculating results, comparing the transfer function calculating results with a transfer function result acquired from the Fourier transform of a measured point spread function, using a minimum mean square error result as a solution; and solving an evaluation value E. The method for detecting the surface shape of a spherical mirror on the basis of phase diversity phase retrieval in a focal plane detector is low in development cost, simple in hardware, susceptible of influences of environment (especially vibration), and capable of dynamically detecting optical elements and systems.

The invention discloses a high-precision method for detecting wave aberration of a system, belonging to the field of optical detection. The method comprises the following steps of: emitting lighting beams by a light source, and generating an ideal spherical wavefront beam through diffraction after entering into a lighting system and a spatial pinhole filter with pinholes; enabling incidence beamsto enter into a detected projection objective, enabling emergent beams with aberration information to generate interference after being diffracted by an optical grating and passing through the spatial filter, acquiring the emergent beams by an image sensor, and carrying out wave surface fitting to obtain an aberration difference; enabling the incidence beams to enter into the detected projection objective through radiating and rotating by 180 DEG to obtain two wavefront measurement results, separating non-rotational symmetry components in system errors by using the characteristic of the Zernike polynomial in a unit circle field, increasing two optical axis exterior point measurements, figuring out the system errors, and subtracting the system errors by a measured value to obtain the actual wave aberration of the detected projection objective. The method for calibrating the system errors of an interferometer in the invention can be used for calibrating the system errors caused by the interferometer and improving the measuring precision of the interferometer.

The invention discloses a Galilean multi-wavelength vary-power laser expanded beam alignment system which consists of a multifocal group plane convex single lens, a fixed group plano-concave single quadric non-spherical lens and a compensating group plano-concave quadric non-spherical lens. The system can continuously expand the beam of any laser wave length having the divergence angle of emergence within 5mrad at the interval of 250-2300nm by vary-power within 2-12 times, and no real convergent point is available in the system, and the system can be applied to the field of intense laser. When in design, a perfect lens is added behind a compensating mirror, so that the obtained the image of the system proves that the wave aberration PV values at center vision field of laser with any wavelength in the whole wave band are superior to lambada / 50, the PV value of 0.7 vision field is basically superior to lambada / 10, the PV value of 1 vision field is superior to lambada / 4, and the alignment effect of the expanded beam is good. The system has simple structure, easy processing and debugging as well as convenient use.

The invention discloses a Ronchi shearing interferometer based phase extraction method. A Ronchi shearing interferometer structure used in the Ronchi shearing interferometer based phase extraction method comprises a light source, a focusing lens, a scattering optical element, one-dimensional diffraction grating plates, a measured optical system platform, chessboard gratings, a two-dimensional photoelectric sensor and a computer. The one-dimensional diffraction grating plates and the chessboard gratings are arranged on an object plane and an image plane of the measured optical system and the phase is calculated due to collection of 9 interferometric fringe patterns with the shifting interval to be a quarter of pi to eliminate influences to the phase extraction accuracy from multi-level diffraction light in Ronchi shearing interference. The Ronchi shearing interferometer based phase extraction method has the advantages of eliminating the influences of diffraction items in higher levels other than the levels 0, 1 and minus 1, reducing the phase extraction system error in wave aberration detection and improving the wave aberration detection accuracy of the optical system.

The invention relates to an online projection objective wave aberration detection device and method. The detection device comprises a light source, a rotary scatterer, a first focusing lens, an optical fiber array, a second focusing lens, a scattering optical element, an object plane optical grating, an image plane optical grating, a two-dimensional photoelectric sensor, a phase-shift control module and a computer, wherein the rotary scatterer is composed of a support, an electric motor and a circular diffusion scattering optical element, and is combined with the multimode optical fiber array for converting a coherent light or partially coherent light source into incoherent light; ten interference fringe patterns with phase shifting amounts of 0, pi / 6, pi / 3, pi / 2, 2pi / 3, 5pi / 6, pi, 5pi / 3, 3pi / 2 and 11pi / 6 respectively are acquired to calculate a phase position and the influence of multilevel diffraction light interference of the optical grating on the phase position extraction precision is eliminated. The device and the method can improve the modulation effect of the object plane optical grating on the optical field spatial coherence so as to achieve a high-precision alignment effect, reduce the system error of phase position extraction in wave aberration detection and improve the wave aberration detection precision of an optical system.

A point-diffraction interference wave aberration measuring instrument consists of a light source, a light splitter, a first light intensity and polarization adjuster, a phase shifter, a second light intensity and polarization adjuster, an ideal wave front generating unit, an object precise adjusting platform, a measured optical system, an image wave front detecting unit, an image precise adjusting platform and a data processing unit. The interference instrument has the advantages of simplicity in structure, no systematic error of a phase shifting element, high interference grain visibility and capability of calibrating the systematic error.

Deviations from optimum values of the exposure light quantity and focus of test and product circuit patterns are predicted from the dimensions of the patterns, illumination conditions and the wave aberration of an exposure lens. A signal waveform of scatterometry of the test pattern is linked to the deviations from the optimum values of the exposure light quantity and focus to form a library. The test pattern after exposed and developed in actual steps is collated with the signal waveform in the library measured by the scatterometry to find deviations from the optimum values of the exposure light quantity and focus of the test pattern. Deviations of the optimum values of a product circuit pattern from the deviations of the test pattern are acquired on the basis of the deviations, and the acquired deviations are fed back to subsequent exposure steps.

A detection system and method of lithography machine projection lens odd chromatic aberration based on two-stage illumination are disclosed, wherein the invention uses the two-stage illumination mode to replace the conventional illumination model so as to optimize the periodic parameter of the phase-shifting grating as the detection in two-stage illumination mode; the detection mark is used for detecting the wave aberration of the lithography machine projection lens; the detection precision is obviously improved.

The invention discloses an optical system wave aberration detection device, relates to the technical field of optical measurement and solves the problem that the existing optical system wave aberration detection device has deflection error and translation error in the phase shift process. Two beams of common-path orthogonal line polarized light emitted from a light splitting system are split by asecond polarization splitting prism, a reference light and a testing light are coupled to a reference optical fiber and a testing optical fiber with a motor-driven polarization controller through a first coupling lens and a second coupling lens; a light emitted from the testing optical fiber is irradiated to a coated end face of the reference optical fiber by a detected optical system and is reflected, a first pyramid prism is adjusted so that a test spherical wave and a reference spherical wave generate interference, a second pyramid lens which is insensitive to the deflection error is movedby a piezoelectric ceramic so as to realize the phase shift process; a second plane mirror enables the wave aberration detection device to be insensitive to the translation error in the phase shift process; an interference image is acquired by using a photoelectric detector, and is input into the computer to be processed and analyzed by using a phase shift algorithm; therefore, the optical systemwave aberration is obtained.

In the case of a method for absolute calibration of an interferometer with the aid of a spherical output wave, comprising an optical element which retroflects the incident spherical wave itself or via a mirror, at least four measuring procedures are undertaken to determine a wave aberration W. The optical element is measured in the at least four measuring positions intrafocally and extrafocally in at least two different rotational angle positions. It is also possible, in addition, to undertake a measurement via a mirror in the cat's eye position (focus 3).

An improved wavefront sensor is provided that enhances the initial focus and precision of imaged spots used to determine the monochromatic wave aberrations of the eye. The wavefront sensor includes an adjustment camera that is independent of a lenslet camera. A laser in a lower power mode is projected onto the retina of the eye and is brought into more precise or sharp focus by a control system employing data from the adjustment camera, which aids in focusing the imaged spots. “Trombone”-type optics are used to adjust the focus of the light projected onto the retina and the imaged spots onto a sensor. The laser has a higher power mode used when acquiring data of the imaged spots from the sensor.

The invention discloses a system and a method for detecting the wave aberration of a photoetching projection objective, and the system and method provided by the invention are used for photoetching machines and based on the centering of principal component fitting of space images. In the invention, an offset between the actually-measured position and nominal position of a space image is found through principal component fitting, thereby obtaining the principal component coefficient and wave aberration of the space image. The method comprises the following steps: firstly, emulating a group of space images, carrying out principal component analysis and linear regression on the space images so as to obtain principal components, a regression matrix, and a spline interpolation function of principal components and emulated space images; scanning the space images by using an X-Z plane used image sensor so as to obtain the space image distribution on the silicon wafer surface of a photoetching machine, then obtaining the offset between the actually-measured position and nominal position of the space image firstly through carrying out a centering process, and then calculating the principalcomponent coefficient corresponding to the offset; and according to the regression matrix and the principal component coefficient, fitting and solving the wave aberration by using the least square method. By using the system and method disclosed by the invention, the centering errors of the space images are compensated, and the solved repeatable accuracy is improved.

The invention provides a large-aperture optical system MTF measuring device and method in order to solve the technical problems that in a traditional large-aperture optical system MTF detecting mode,the testing precision is easily affected by the surface shape of an optical element in a large-aperture collimator, the disturbance resisting capacity is poor, and the testing cost is high. Accordingto the invention, a small-aperture plane mirror is used as a reference plane mirror, an active Hartmann wavefront sensor is used as wavefront measurement equipment, the small-aperture plane mirror ismoved to each sub-aperture position of a large-aperture optical system, and the active Hartmann wavefront sensor is used to acquire the wave aberration of each sub-aperture. When the full aperture iscompletely covered, sub-aperture wave aberration data are spliced by adopting a sub-aperture splicing algorithm to obtain full aperture wave aberration, and the full aperture wave aberration can be converted into an MTF value of an optical system after numerical calculation. According to the invention, the use of an interferometer and a large-aperture plane mirror is avoided, the anti-disturbancecapability of the whole system is improved, and the test cost is reduced.

The invention provides a measuring device for determining the optimal focal plane position of a lithography machine and a method thereof. The device comprises an illuminated light source system, a projection objective imaging system, a masking table, a workbench, a wave aberration sensor and an interferometer for precisely positioning, wherein the masking table is sued for supporting and fixing a mask plate, and the workbench is used for supporting and fixing a wafer. The method deduces the conversion relationship between outoffocus and other image differences, a wave aberration sensor detects the wave aberration of an optical imaging system on different out-of-focus positions, and the optimal focal plane position of the lithography machine can be obtained by calculation according to a measuring result. The measuring device and the method of the invention can measure the optimal focal plane position of the lithography machine.

The invention relates to a wave aberration measuring device and method. An illumination system produces an illumination beam; an object surface small hole comprises at least two object surface small hole marks, the at least two object surface small hole marks are arranged along a first direction, the object surface small hole marks comprise two object surface small hole sub marks, the two object surface small hole sub marks are arranged along a second direction, the first direction is vertical to the second direction, the grating directions of the two object surface small hole sub marks are respectively an X direction and a Y direction, and the illumination beam irradiates the object surface small hole to form a measuring beam; the measuring beam passes through a projection objective lens and then shoots an image surface shear grating so as to form a shear interference pattern; and a two-dimensional array photosensitive element obtains a plurality of shear interference patterns in the two directions through repeatedly changing the relative positions of the object surface small holes and the shear interference pattern, so as to calculate the wave aberration of the projection objective lens. According to the wave aberration measuring device and method, the wave aberration of multi-view-field points can be measured, so that the parallel measurement on the wave aberration of the multi-view-field points of a photoetching device is realized; and the measuring speed is fast, and the real-time performance is high.

The invention relates to a system capable of solving an inclination problem of a narrow field of view lens in a wave aberration detection process and a method thereof. The system comprises a laser interferometer, a pentagonal prism, an autocollimation theodolite, a planar mirror and an optical axis directional tool which is in common optical axis with a narrow field of view lens to be detected. The laser interferometer, the pentagonal prism, the optical axis directional tool and the planar mirror are provided on a same optical path in order. The pentagonal prism is provided on an emitting optical path of the autocollimation theodolite. The system capable of solving the inclination problem of the narrow field of view lens in wave aberration detection and the method thereof have the characteristics of high detection precision, a short detection period and good repeatability.

The invention relates to a power amplifier in digit method, wherein it is formed by sampling filter, noise, noise rectifying circuit, dead area control circuit, output driving circuit, and band-pass filter circuit. The power amplifier works at switch mode, while the switch frequency is higher than maximum input frequency; all parts beside power element are based on digit method. The inventive amplifier has high efficiency, low harmonic wave aberration, and low thermal consumption.

The invention discloses a photoetching machine projection objective lens wave aberration field measurement method, which utilizes a measurement system. The system comprises a light source, a lighting system, a mask table, a projection objective lens, a six-dimensional scanning worktable and an image sensor, wherein the light source is used for generating lighting light beams; the lighting system is used for adjusting the lighting light beams; the mask take can carry a test mask and position accurately; the projection objective lens can image a graph on the test mask and has an adjustable numerical aperture; the six-dimensional scanning worktable can position accurately; the image sensor is arranged on the six-dimensional scanning worktable and is used for measuring the image of the graph on the test mask; and the lighting system can adjust a beam waist size, light intensity distribution, a partial coherence factor and a lighting mode. When in measurement, the light intensity distribution of an aerial image is simulated and analyzed and a linear model of a Zernike coefficient is established based on the simulation and analysis first and then the Zernike coefficient is obtained by fitting by utilizing the linear model according to the aerial image measured by the image sensor.

A transmissive artificial crystal wave aberration Hartman measuring instrument mainly comprises a light source, a beam filtering system, an internal focusing mechanism, a pore opening size segmentation element, a photodetector and a computer. A Hartman wave-front sensor is composed of the pore opening size segmentation element and the photodetector. Lights given off by the light source are filtered by the beam filtering system and are emitted after being collimated into parallel lights and pass through an artificial crystal to be measured. Carrying artificial crystal wave aberration information, transmission light waves enter the internal focusing mechanism. The diopter of the artificial crystal is compensated by the internal focusing device. The compensated light waves are segmented and sampled by the pore opening size segmentation element and are focused on the photodetector to form light spot arrays. Light spot data is collected and sent to the computer to obtain the total aberration of the artificial crystal to be measured after being processed. The transmissive artificial crystal wave aberration Hartman measuring instrument has the advantage of simple and stable structure, which can provide a convenient, fast and reliable detection for the ophthalmology clinical artificial crystal transplantation and processing and the detection of artificial crystals for personalized human eye aberrations correcting.

A device for detecting system wave aberration of a photoetchingprojection objective comprises a light source, an illuminating system, a pinhole space filter, a beamsplitter, a to-be-detected projection objective, a spherical reflector, a two-dimensional grating, a space filter and an image sensor. According to the device, a level selection window is taken as the space filter, so that noise is reduced, the measuring accuracy is improved, and the defect of limitation of Talbot distance to the image sensor position is overcome. The spherical reflector is added to a light path, can be used for detection of system wave aberration of an immersedprojection objective and can also be used for detection of system wave aberration of a non-immersedprojection objective; full-field system wave aberration of the projection objective can be detected, and wave aberration represented by 36 Zernike coefficients is obtained; and with adoption of a light path structure of a shearing interferometer, the device has the advantages of high detecting accuracy, good repeatability and the like.

Disclosed are a digital phase-shifting lateral shearing interferometer and an optical system wave aberration measurement method. The interferometer is composed of a light source, a small-hole mask, a first spatial light modulator, a second spatial light modulator, a two-dimensional photoelectric detector and a computer. The first spatial light modulator is arranged as a grating by computer programming to serve as a shearing light splitter, the second spatial light modulator is arranged as a double-window mask to serve as a filter for filtering high-order diffraction light at zero order and more than two orders, and only diffraction light at +1 order and -1 order takes part in interference. The problem that the high-order diffraction light takes part in interference is solved, the interferometer has the advantage that changeable shearing direction and adjustable shearing rate can be realized without replacing or rotating any device.