Abstract: An inspection system includes a radiation source that generates a beam of radiation and irradiates a first surface of an object, defining a region of the first surface of the object. The radiation source also irradiates a second surface of the object, defining a region of the second surface, wherein the second surface is at a different depth level within the object than the first surface. The inspection system may also include a detector that defines a field of view (FOV) of the first surface including the region of the first surface, and receives radiation scattered from the region of the first surface and the region of the second surface. The inspection system may also include a processor that discards image data not received from the region of the first surface, and constructs a composite image comprising the image data from across the region of the first surface.

Abstract: A system includes an illumination system, an optical element, and a detector. The optical system is implemented on a substrate. The illumination system includes first and second sources and first and second generators. The illumination system generates a beam of radiation. The first and second sources generate respective first and second different wavelength bands. The first and second resonators are optically coupled to respective ones of the first and second sources and narrow respective ones of the first and second wavelength bands. The optical element directs the beam toward a target structure. The detector receives radiation from the target structure and to generate a measurement signal based on the received radiation.

Abstract: A compact sensor apparatus having an illumination beam, a beam shaping system, a polarization modulation system, a beam projection system, and a signal detection system. The beam shaping system is configured to shape an illumination beam generated from the illumination system and generate a flat top beam spot of the illumination beam over a wavelength range from 400 nm to 2000 nm. The polarization modulation system is configured to provide tenability of linear polarization state of the illumination beam. The beam projection system is configured to project the flat top beam spot toward a target, such as an alignment mark on a substrate. The signal detection system is configured to collect a signal beam comprising diffraction order sub-beams generated from the target, and measure a characteristic (e.g., overlay) of the target based on the signal beam.

Abstract: Systems, apparatuses, and methods are provided for manufacturing a wafer clamp having hard burls. The method can include providing a first layer that includes a first surface. The method can further include forming a plurality of burls over the first surface of the first layer. The forming of the plurality of burls can include forming a subset of the plurality of burls to a hardness of greater than about 6.0 gigapascals (GPa).

Abstract: A system, method, a lithographic apparatus and a software product configured to determine a drift in an attribute of an illumination and a corresponding drift correction. The system includes a lithographic apparatus that includes at least two sensors, each configured to measure a property related to an illumination region provided for imaging a substrate. Furthermore, a processor is configured to: determine, based on a ratio of the measured property, a drift of the illumination region with respect to a reference position; determine, based on the drift of the illumination region, a drift in an attribute related to the illumination upstream of the illumination region measured by the at least two sensors, and determine, based on the drift in the attribute, the drift correction to be applied to the attribute to compensate for the drift in the attribute.

Abstract: Systems, apparatuses, and methods are provided for manufacturing an electrostatic clamp. An example method can include forming, during a first duration of time comprising a first time, a top clamp comprising a first set of electrodes and a plurality of burls. The method can further include forming, during a second duration of time comprising a second time that overlaps the first time, a core comprising a plurality of fluid channels configured to carry a thermally conditioned fluid. The method can further include forming, during a third duration of time comprising a third time that overlaps the first time and the second time, a bottom clamp comprising a second set of electrodes. In some aspects, the example method can include manufacturing the electrostatic clamp without an anodic bond.

Abstract: A metrology method relating to measurement of a structure on a substrate, the structure being subject to one or more asymmetric deviation. The method includes obtaining at least one intensity asymmetry value relating to the one or more asymmetric deviations, wherein the at least one intensity asymmetry value includes a metric related to a difference or imbalance between the respective intensities or amplitudes of at least two diffraction orders of radiation diffracted by the structure; determining at least one phase offset value corresponding to the one or more asymmetric deviations based on the at least one intensity asymmetry value; and determining one or more measurement corrections for the one or more asymmetric deviations from the at least one phase offset value.

Abstract: A detection system (200) includes an illumination system (210), a first optical system (232), a phase modulator (220), a lock-in detector (255), and a function generator (230). The illumination system is configured to transmit an illumination beam (218) along an illumination path. The first optical system is configured to transmit the illumination beam toward a diffraction target (204) on a substrate (202). The first optical system is further configured to transmit a signal beam including diffraction order sub-beams (222, 224, 226) that are diffracted by the diffraction target. The phase modulator is configured to modulate the illumination beam or the signal beam based on a reference signal. The lock-in detector is configured to collect the signal beam and to measure a characteristic of the diffraction target based on the signal beam and the reference signal. The function generator is configured to generate the reference signal for the phase modulator and the lock-in detector.

Abstract: Embodiments herein describe methods, devices, and systems for reducing an electric field at a clamp-reticle interface using an enhanced electrostatic clamp. In particular, the electrostatic clamp includes a clamp body, an electrode layer disposed on a top surface of the clamp body, and a plurality of burls that project from a bottom surface of the clamp body, wherein the electrode layer comprises a plurality of cutouts at predetermined locations that vertically correspond to locations of the plurality of burls at the bottom surface of the clamp body.

Abstract: Methods and systems are described for reducing particulate contaminants on a clamping face of a clamping structure in a lithographic system. A substrate such as a cleaning reticle is pressed against the clamping face. A temperature differential is established between the substrate and the clamping face either before or after clamping occurs to facilitate transfer of particles from the clamping face to the substrate.

Abstract: A method to reduce sensitivity of a level sensor, arranged to measure a height of a substrate, to variations of a property of an optical component in the level sensor includes directing a beam of radiation toward a diffractive element and directing the beam, via an optical system, to a first reflective element at a first angle of incidence. The beam has a first polarization and a second polarization that is perpendicular to the first polarization. The first reflective element reflects the beam toward a second reflective element at a second angle of incidence causing the beam to impinge on the substrate. The first and second angles of incidence are selected to reduce variations of a ratio of intensities of the first polarization to the second polarization of the beam imparted by a property of a layer of at least one of the first and second reflective elements.

Abstract: An optical element and a lithographic apparatus including the optical element. The optical element includes a first member having a curved optical surface and a heat transfer surface, and a second member that comprises at least one recess, the at least one recess sealed against the heat transfer surface to form at least one closed channel between the first member and the second member to allow fluid to flow therethrough for thermal conditioning of the curved optical surface. In an embodiment, one or more regions of the heat transfer surface exposed to the at least one closed channel are positioned along a curved profile similar to that of the curved optical surface.

Abstract: An apparatus and system for determining alignment of a substrate in which a periodic alignment mark is illuminated with spatially coherent radiation which is then provided to a compact integrated optical device to create self images of the alignment mark which may be manipulated (e.g., mirrored, polarized) and combined to obtain information on the position of the mark and distortions within the mark. Also disclosed is a system for determining alignment of a substrate in which a periodic alignment mark is illuminated with spatially coherent radiation which is then provided to an optical fiber arrangement to obtain information such as the position of the mark and distortions within the mark.

Abstract: An alignment apparatus includes an illumination system configured to direct one or more illumination beams towards an alignment target and receive the diffracted beams from the alignment target. The alignment apparatus also includes a self-referencing Interferometer configured to generate two diffraction sub-beams, wherein the two diffraction sub-beams are orthogonally polarized, rotated 180 degrees with respect to each other around an alignment axis, and spatially overlapped. The alignment apparatus further includes a beam analyzer configured to generate interference between the overlapped components of the diffraction sub-beams and produce two orthogonally polarized optical branches, and a detection system configured to determine a position of the alignment target based on light intensity measurement of the optical branches, wherein the measured light intensity is temporally modulated by a phase modulator.

Abstract: Apparatus for, and method of, measuring a parameter of an alignment mark on a substrate in which an optical system is arranged to receive at least one diffraction order from the alignment mark and the diffraction order is modulated at a pupil or a wafer conjugate plane of the optical system, a solid state optical device is arranged to receive the modulated diffraction order, and a spectrometer is arranged to receive the modulated diffraction order from the solid state optical device and to determine an intensity of one or more spectral components in the modulated diffraction order.

Abstract: A cleaning tool configured to be inserted into a lithography apparatus in a first configuration, configured to be engaged by a handler of the lithography apparatus, and used for cleaning a portion of the lithography apparatus. The cleaning tool is configured to move from the first configuration to a second, expanded configuration, after engagement by the handler such that the cleaning tool is in the second configuration when used for cleaning the portion of the lithography apparatus. There may also be a container configured to hold the cleaning tool in the first configuration and fit into the lithography apparatus. In that case, the cleaning tool is configured to be inserted into the lithography apparatus in the container, moved from the container by the handler for the cleaning, and returned to the container by the handler after the cleaning.

Abstract: A calibration system includes a plate, a fixed alignment mark, and a variable diffraction grating. The plate is adjacent to a wafer alignment mark disposed on a wafer. The fixed alignment mark is disposed on the plate and is configured to act as a reference mark for an initial calibration of the calibration system. The variable diffraction grating is disposed on the plate and includes a plurality of unit cells configured to form a plurality of variable alignment marks. The variable diffraction grating is configured to calibrate a shift-between-orders of one of the variable alignment marks and the fixed alignment mark.

Abstract: A method for source mask optimization or mask only optimization used to image a pattern onto a substrate. The method includes determining a non-uniform illumination intensity profile for illumination; and determining one or more adjustments for the pattern based on the non-uniform illumination intensity profile until a determination that features patterned onto a substrate substantially match a target design. The non-uniform illumination intensity profile may be determined based on an illumination optical system and projection optics of a lithographic apparatus. In some embodiments, the lithographic apparatus includes a slit, and the non-uniform illumination profile is a through slit non-uniform illumination intensity profile. Determining the one or more adjustments for the pattern may include performing optical proximity correction, for example.

Abstract: Methods and systems are described for reducing adhesion and controlling friction between a wafer and a wafer table during semiconductor photolithography wherein the tops of burls on the wafer table have a layer with a nanoscale topography.

Abstract: A method of applying a measurement correction includes determining an orthogonal subspace used to characterize a first principal component of the measurement and a second principal component of the measurement, and rotating the orthogonal subspace by a first angle such that the first principle component rotates to become a first factor vector and the second principle component rotates to become a second factor vector. An asymmetry vector is generated by rotating the second factor vector by a second angle, where the asymmetry vector and the first factor vector define a non-orthogonal subspace. An asymmetry contribution is determined in the measurement based on the projection of the measurement onto the first factor vector in the non-orthogonal subspace. The method also includes subtracting the asymmetry contribution from the measurement.