Abstract: A method of mapping a target region image to a referenced image includes steps of acquiring the target region image. The method also includes acquiring the referenced image overlapping the target region image. The method further includes determining a number of common subregions in an intersection of the referenced image and the target region image, determining offsets between the common subregions, computing a distortion map of the target region image over the intersection, and remapping the target region image to match the reference image. The method can be utilized in a Unmanned Aerial Vehicle (UAV) and the target image can be a SAR image.

Abstract: Systems and methods relating to assessing a navigation subsystem are provided. One method includes: acquiring a ground image associated with a nominal position; assigning one or more texture classes to each of a plurality of pixels of the ground image; partitioning the processed ground image into a plurality of ground image sub regions; retrieving a reference image from an atlas of reference images; generating a plurality of matching statistics comprising a matching statistic for each ground image sub region by comparing the ground image sub region to a portion of the reference image; calculating a calculated position of the ground image and an uncertainty associated with the calculated position based on the matching statistics; and determining critique data associated with the navigation subsystem based on a comparison of the calculated position of the ground image with at least one position determined by the navigation subsystem.

Abstract: Systems and methods relating to assessing a navigation subsystem are provided. One method includes: acquiring a ground image associated with a nominal position; assigning one or more texture classes to each of a plurality of pixels of the ground image; partitioning the processed ground image into a plurality of ground image sub regions; retrieving a reference image from an atlas of reference images; generating a plurality of matching statistics comprising a matching statistic for each ground image sub region by comparing the ground image sub region to a portion of the reference image; calculating a calculated position of the ground image and an uncertainty associated with the calculated position based on the matching statistics; and determining critique data associated with the navigation subsystem based on a comparison of the calculated position of the ground image with at least one position determined by the navigation subsystem.

Abstract: A method for mapping a target image to a reference image includes receiving a target image; receiving a reference image that overlaps the target image; preprocessing the target image, wherein the preprocessing includes: rejecting a target image with a shadow region above a shadow threshold while keeping a target image with a shadow region below a shadow threshold; providing an uncertainty in a location of the kept target image relative to the reference image; transforming the kept target image to an atlas projection to match the reference image; partitioning the transformed kept target image into a sub-region; and determining a matching statistic for each sub-region to determine a location for each sub-region relative to the reference image.

Abstract: A method for mapping a target image to a reference image includes receiving a target image; receiving a reference image that overlaps the target image; preprocessing the target image, wherein the preprocessing includes: rejecting a target image with a shadow region above a shadow threshold while keeping a target image with a shadow region below a shadow threshold; providing an uncertainty in a location of the kept target image relative to the reference image; transforming the kept target image to an atlas projection to match the reference image; partitioning the transformed kept target image into a sub-region; and determining a matching statistic for each sub-region to determine a location for each sub-region relative to the reference image.

Abstract: A method of mapping a target region image to a referenced image includes steps of acquiring the target region image. The method also includes acquiring the referenced image overlapping the target region image. The method further includes determining a number of common subregions in an intersection of the referenced image and the target region image, determining offsets between the common subregions, computing a distortion map of the target region image over the intersection, and remapping the target region image to match the reference image. The method can be utilized in a Unmanned Aerial Vehicle (UAV) and the target image can be a SAR image.

Abstract: A method and apparatus for determining the state of the lens transmittance of an optical projection system are described. A lens or imaging objective transmission is determined as a function of exit pupil transverse direction cosine (nx,ny) at multiple field points thereby providing a more complete analysis and correction of a photolithographic exposure system. The entrance pupil of a projection imaging system is uniformly illuminated and the angular dependence of transmission through the imaging system as a function of exit pupil direction cosines is determined. The illumination source includes a light conditioner with an in-situ illumination structure (ISIS), which is an optical structure that can provide uniform illumination of the system's entrance pupil.

Abstract: A wafer stage overlay error map is created using standard overlay targets and a special numerical algorithm. A reticle including a 2-dimensional array of standard overlay targets is exposed several times onto a photoresist coated silicon wafer using a photolithographic exposure tool. After exposure, the overlay targets are measured for placement error using a conventional overlay metrology tool. The resulting overlay error data is then supplied to a software program that generates a 2-dimensional wafer stage distortion and yaw overlay error map.

Abstract: Intra-field distortion for a projection imaging tool is determined using a self-referenced rectangular grid reticle pattern, that includes at least two arrays of alignment attributes that are complementary to each other, is exposed multiple times onto a substrate with a recording media. A reference reticle pattern is exposed onto the substrate, wherein the reference reticle pattern overlaps the grid alignment attributes thereby creating completed grid alignment attributes. Positional offsets of the completed alignment attributes and completed grid alignment attributes are measured and an intra-field distortion from the offsets is determined.

Abstract: An apparatus and method for the simultaneous determination of focus and source boresighting error for photolithographic steppers and scanners is described. A reticle containing custom arrays of box-in-box test structures specifically designed for performing source or exit pupil division using an aperture plate is exposed onto a resist coated wafer several times. The resulting exposure patterns are measured with a conventional overlay tool. The overlay data is processed with a slope-shift algorithm for the simultaneous determination of both focus and source telecentricity as a function of field position. Additionally, methods for ameliorating metrology induced effects and methods for producing precision Bossung curves are also described. This Abstract is provided for the sole purpose of complying with the Abstract requirement rules, it shall not be used to interpret or to limit the scope or the meaning of the claims.

Abstract: A method and apparatus for resolving both the angular (nx,ny) and spatial (x,y) dependence of the effective source coherence matrix for lithographic steppers and scanners is described. First an in-situ source metrology instrument is combined with in-situ polarization elements to create an in-situ source imaging polarizer or ISIP. The ISIP is loaded into a photolithographic exposure tool, aligned, and then exposed onto a suitable recording media or recording sensor. The recording sensor comprising either resist coated wafers or electronic sensors capture the image intensity at a multiplicity of different field points. The resulting measurements are entered into a computer program that reconstructs the source coherence matrix as a function of direction cosine at multiple field points. Alternative ISIP configurations are discussed in some detail. Applications of the ISIP include polarization source mapping for deep-UV and EUV lithography, process optimization, process monitoring, and chip manufacturing.

Abstract: A method and apparatus for determining the state of the lens transmittance of an optical projection system are described. A lens or imaging objective transmission is determined as a function of exit pupil transverse direction cosine (nx,ny) at multiple field points thereby providing a more complete analysis and correction of a photolithographic exposure system. The entrance pupil of a projection imaging system is uniformly illuminated and the angular dependence of transmission through the imaging system as a function of exit pupil direction cosines is determined. The illumination source includes a light conditioner with an in-situ illumination structure (ISIS), which is an optical structure that can provide uniform illumination of the system's entrance pupil.

Abstract: A technique for the determination of dynamic lens field curvature uniquely associated with a photolithographic scanner is described. A series of lithographic exposures is performed on a resist coated silicon wafer using a photolithographic scanner. The lithographic exposures produce an array of focusing fiducials that are displaced relative to each other in a unique way. The resulting measurements are fed into a computer algorithm that determines the dynamic lens field curvature (ZDLC) perpendicular to the scanning direction in an absolute sense. Furthermore, the effects of wafer flatness, wafer surface non-uniformity, and stage error are considered. The ZDLC information can be used to improve lithographic modeling, overlay modeling, and advanced process control techniques related to scanner stage dynamics.

Abstract: A method and apparatus for embedded encoding of overlay data ordering in an in-situ interferometer is described. An in-situ interferometer is encoded, or augmented, with special or missing alignment attributes at desired positions. Exposing a sequence of the encoded in-situ interferometer onto a silicon wafer coated with a suitable recording media. Then measuring the alignment attributes. The encoded overlay data is processed to verify the proper order and physical location of each overlay measurement. The data is collected without increasing the overall number of required overlay measurements required. Collection of overlay data allows for the proper reconstruction of the aberrated wavefront. Non-coupling alignment attribute offsets can also be used to perform similar operations using singular value decomposition and null space operations.

Abstract: A method and apparatus for measuring the chromatic response of lithographic projection imaging systems is described. An apparatus for determining the lens aberrations for a lithographic projection lens is provided. A substrate coated with a suitable recording media is provided. A series of lithographic exposures are performed using an exposure source with variable spectral settings. The exposures are measured, and the measurements are used to determine a chromatic response of the projection imaging system.

Abstract: An in-situ interferometer includes an image modifying optic that produces light ray bundles. The light ray bundles are projected onto a reticle with a plurality of measurement fiducials encoded onto a face of the reticle. The measurement fiducials are exposed onto a sensing plane and their locations measured. Aberrations in the projection system are determined from the measurements of the exposed reticles.

Abstract: A method and apparatus for determining lens distortion in a projection imaging tool are described. The techniques include exposing at least one alignment attribute onto a substrate having a recording media. A complementary alignment attribute is also exposed onto the substrate such that the complementary alignment attribute and alignment attribute form a completed alignment attribute. The exposure of the alignment attributes, or the complementary alignment attribute, or both, may be accomplished by multiple sub nominal dose exposures. Intra field distortion of the projection imaging tool is determined from measurements of the exposed completed alignment attributes. The alignment attributes and complimentary alignment attribute may be part of a reticle. The transmission of the alignment attribute may be different than the transmission of the complementary alignment attribute.

Abstract: An apparatus and method for manufacturing and using a calibrated registration reference wafer in a semiconductor manufacturing facility where an archive media includes etched alignment attributes. Exposing a pattern of complementary alignment attributes onto the archive media such that the pattern of complementary alignment attributes overlay and interlock with the etched alignment attributes thereby forming completed alignment attributes. Then, measuring offsets in the completed alignment attributes and constructing a calibration file for the archive media based upon the offset measurements and other characteristic data of the exposure tool.

Abstract: A method and apparatus for front to back substrate registration is described. Alignment characteristics of features on surfaces of substrates can be used to physically align substrates with a multiplicity of integrated alignment optics. Measurement of offsets of the integral alignment optics are used to compute registration data for use in calibration of the substrate global alignment.

Abstract: A process for the determination of focal plane deviation uniquely due to the lens field curvature associated with a photolithographic projection tool is described. A series of lithographic exposures is performed on a resist coated silicon wafer using a stepper or scanner running in static mode. The lithographic exposures produce an array of focusing fiducials that are displaced relative to each other in a unique way. The resulting measurements are fed into a computer algorithm that calculates the lens field curvature in an absolute sense in the presence of wafer height variation and varying stage performance.