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.

Abstract: A system (500) includes an illumination system (502), a lens element (506), and a detector (504). The illumination system generates a beam of radiation (510) having a first spatial intensity distribution (800) at a pupil plane (528) and a second spatial intensity distribution (900) at a plane of a target (514). The first spatial intensity distribution comprises an annular intensity profile (802) or an intensity profile corresponding to three or more beams. The lens element focuses the beam onto the target. The second spatial intensity distribution is a conjugate of the first intensity distribution and has an intensity profile corresponding to a central beam (902) and one or more side lobes (904) that are substantially isolated from the central beam. The central beam has a beam diameter of approximately 20 microns or less at the target. The detector receives radiation scattered by the target and generates a measurement signal based on the received radiation.

Abstract: An apparatus for reticle sub-field thermal control in a lithography system is disclosed. The apparatus includes a clamp configured to fix an object. The clamp includes a plurality of gas distribution features that are spatially arranged in a pattern. The apparatus further includes a gas pressure controller configured to individually control a gas flow rate through each of the plurality of gas distribution features to spatially modulate a gas pressure distribution in a space between the clamp and the object. The gas distribution features include a plurality of trenches or holes arranged in an array form.

Abstract: A method of applying a measurement correction includes determining an orthogonal subspace used to characterize the measurement as a plot of data. A first axis of the orthogonal subspace corresponds to constructive interference output from an interferometer of the metrology system plus a first error variable and a second axis of the orthogonal subspace corresponds to destructive interference output from the interferometer of the metrology system plus a second error variable. The method also includes determining a slope of the plot of data and determining a fitted line to the plot of data in the orthogonal subspace based on the slope.

Abstract: Disclosed is a method for a metrology measurement on an area of a substrate comprising at least a portion of a target structure. The method comprises receiving a radiation information representing a portion of radiation scattered by the are, and using a filter in a Fourier domain for removing or suppressing at least a portion of the received radiation information that does not relate to radiation that has been scattered by the target structure for obtaining a filtered radiation information for the metrology measurement, wherein characteristics of the filter are based on target information about the target structure.

Abstract: A system includes a radiation source and a phased array. The phased array includes optical elements, waveguides and phase modulators. The phased array generates a beam of radiation. The optical elements radiate radiation waves. The waveguides guide radiation from the radiation source to the optical elements. The phase modulators adjust phases of the radiation waves such that the radiation waves accumulate to form the beam. An amount of incoherence of the beam is based on randomization of the phases.

Abstract: An alignment method includes directing an illumination beam with a varying wavelength or frequency towards an alignment target, collecting diffraction beams from the alignment target and directing towards an interferometer. The alignment method also includes producing, by the interferometer, two diffraction sub-beams from the diffraction beams, wherein the diffraction sub-beams are orthogonally polarized, rotated 180 degrees with respect to each other around an alignment axis, and spatially overlapped. The alignment method further includes measuring interference intensity of the diffraction beams based on a temporal phase shift, wherein the temporal phase shift is a function of the varying wavelength or frequency of the illumination beam and a fixed optical path difference between the diffraction beams. The alignment method also includes determining a position of the alignment target from the measured interference intensity.

Abstract: An apparatus for and method of sensing alignment marks in which a self-referencing interferometer based sensor outputs standing images of the alignment marks and camera device is used to capture the images as output by the sensor and a detector is used to obtain phase information about the alignment marks from the images as output by the sensor.

Abstract: A sensor apparatus includes a sensor chip, an illumination system, a first optical system, a second optical system, and a detector system. The illumination system is coupled to the sensor chip and transmits an illumination beam along an illumination path. The first optical system is coupled to the sensor chip and includes a first integrated optic to configure and transmit the illumination beam toward a diffraction target on a substrate, disposed adjacent to the sensor chip, and generate a signal beam including diffraction order sub-beams generated from the diffraction target. The second optical system is coupled to the sensor chip and includes a second integrated optic to collect and transmit the signal beam from a first side to a second side of the sensor chip. The detector system is configured to measure a characteristic of the diffraction target based on the signal beam transmitted by the second optical system.

Abstract: A sensor apparatus includes an illumination system, a detector system, and a processor. The illumination system is con-figured to transmit an illumination beam along an illumination path and includes an adjustable optic. The adjustable optic is configured to transmit the illumination beam toward a diffraction target on a substrate that is disposed adjacent to the illumination system. The transmitting generates a fringe pattern on the diffraction target. A signal beam includes diffraction order sub-beams that are diffracted by the diffraction target. The detector system is configured to collect the signal beam. The processor is configured to measure a char-acteristic of the diffraction target based on the signal beam. The adjustable optic is configured to adjust an angle of incidence of the illumination beam on the diffraction target to adjust a periodicity of the fringe pattern to match a periodicity of the diffraction target.

Abstract: A system designed to couple a patterning device to a support structure having a plurality of burls includes a camera module, an actuator, and a controller. The camera module is designed to capture image data of a backside of the patterning device. The actuator is coupled to at least one burl of the plurality of burls and is designed to move the at least one burl. The controller is designed to receive the image data captured from the camera module and determine one or more locations of contamination on the backside of the patterning device from the image data. The controller is also designed to control the actuator to move the at least one burl of the plurality of burls away from the one or more locations of contamination on the backside of the patterning device, based on the determined locations of contamination.

Abstract: A method of forming an anti-reflection layer, the method including applying a first mixture to an object, the first mixture made from a combination of aluminum tri-sec-butoxide (ATSB), a first chelating agent, water and an alcohol; removing a majority of the alcohol from the applied first mixture; after the removing, applying a second mixture to the object, the second mixture made from a combination of aluminum tri-sec-butoxide, a second chelating agent different than the first chelating agent, water and an alcohol; and removing a majority of the alcohol from the applied second mixture, wherein the applied first and second mixtures are used to form the anti-reflection layer.

Abstract: A reticle transport system having a magnetically levitated transportation stage is disclosed. Such a system may be suitable for use in vacuum environments, for example, ultra-clean vacuum environments.

Abstract: A mode control system and method for controlling an output mode of a broadband radiation source including a photonic crystal fiber (PCF). The mode control system includes at least one detection unit configured to measure one or more parameters of radiation emitted from the broadband radiation source to generate measurement data, and a processing unit configured to evaluate mode purity of the radiation emitted from the broadband radiation source, from the measurement data. Based on the evaluation, the mode control system is configured to generate a control signal for optimization of one or more pump coupling conditions of the broadband radiation source. The one or more pump coupling conditions relate to the coupling of a pump laser beam with respect to a fiber core of the photonic crystal fiber.

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: A system for and method of processing a wafer in which a scan signal is analyzed locally to extract information about alignment, overlay, mark quality, wafer quality, and the like.

Abstract: Methods and systems are described for reducing particles in the vicinity of an electrostatic chuck (300) in which a cleaning reticle or substrate (320) is secured to the chuck, the cleaning reticle or substrate having surfaces partially devoid of conductive material so that an electric field from the chuck can pass through to a volume adjacent the substrate to draw particles (360) in the volume to the surface of the substrate. Voltage supplied to the chuck may have an alternating polarity to enhance the attraction of particles to the surface.

Abstract: An electrostatic clamp for supporting a substrate includes a substrate region, an electrode region at an edge of the substrate region, a support layer, an electrically conductive layer, a contact layer, and an electrode. The support layer has a body having first and second surfaces that are substantially parallel to each other and disposed on opposite sides of the body. A through-hole is disposed in the electrode region and provides access between the first and second surfaces. The electrically conductive layer is disposed on the second surface of the support layer. The contact layer disposed on the electrically conductive layer. The contact layer is uninterrupted in the electrode region and comprises burls in the substrate region. The burls contact the substrate when the electrostatic clamp is supporting the substrate. The electrode is disposed in the through-hole and is electrically coupled to the electrically conductive layer.

Abstract: Methods, computer program products, and apparatuses for reducing sticking during a lithography process are disclosed. An exemplary method of reducing sticking of an object to a modified surface that is used to support the object in a lithography process can include controlling a light source to deliver light to a native surface thereby causing ablation of at least a portion of the native surface to increase the roughness of the native surface thereby forming the modified surface. The increased roughness reduces the ability of the object to stick to the modified surface.

Abstract: A lithographic apparatus includes a clamp (406) configured to receive an object (402). The clamp defines at least one channel (408) configured to pass a fluid at a first fluid temperature. The lithographic apparatus also includes a chuck (404) coupled to the clamp. The chuck (404) defines at least one void (464) configured to thermally insulate the chuck from the clamp.