Abstract: An apparatus and method to determine a property of a substrate by measuring, in the pupil plane of a high numerical aperture lens, an angle-resolved spectrum as a result of radiation being reflected off the substrate. The property may be angle and wavelength dependent and may include the intensity of TM- and TE-polarized radiation and their relative phase difference.

Abstract: An apparatus and method to determine a property of a substrate by measuring, in the pupil plane of a high numerical aperture lens, an angle-resolved spectrum as a result of radiation being reflected off the substrate. The property may be angle and wavelength dependent and may include the intensity of TM- and TE-polarized light and their relative phase difference.

Abstract: For angular resolved spectrometry a radiation beam is used having an illumination profile having four quadrants is used. The first and third quadrants are illuminated whereas the second and fourth quadrants aren't illuminated. The resulting pupil plane is thus also divided into four quadrants with only the zeroth order diffraction pattern appearing in the first and third quadrants and only the first order diffraction pattern appearing in the second and third quadrants.

Abstract: A method is provided for determining an actual profile of an object printed on a substrate. The method can include receiving an actual spectrum signal associated with the object, selecting a first model profile, and generating a first model spectrum signal associated with the first model profile. The method can further include comparing the first model spectrum signal with the actual spectrum signal. If the first model spectrum signal and the actual spectrum signal do not match a desired tolerance, the aforementioned selecting, generating, and comparing can be repeated with a second model profile. The second model profile can be selected based on the first model spectrum signal having undergone an optimization process based on a number of variable parameters of the first model profile, where the number of variable parameters is reduced by approximating the first model profile to a single shape with a reduced number of variable parameters.

Abstract: Simultaneous measurement of two orthogonally polarized beams upon diffraction from a substrate is done to determine properties of the substrate. Linearly polarized light sources with their radiation polarized in orthogonal directions are passed via two non-polarizing beamsplitters, one rotated by 90° with respect to the other. The combined beam is then diffracted off a substrate before being passed back through a non-polarizing beamsplitter and through a phase shifter and a Wollaston prism before being measured by a CCD camera. In this way, the phase and intensities for various phase steps of the two polarized beams may thereby be measured and the polarization state of the beams may be determined. If the phase shifter is turned to zero (i.e. with no phase shifting), the grating of the substrate has its parameters measured with TE and TM polarized light simultaneously with the same detector system.

Abstract: Measurement of a profile of a scatterometry object on top of one or more product layers on a substrate is disclosed. To prevent an unknown parameters of one or more product layers having an effect on the measurement of the object profile, the thickness of the one or more product layers is measured prior to measuring the profile of the scatterometry object on the layer(s). In an embodiment, each of a plurality of product layers is measured as it is exposed so that only the degree of freedom of the most recently exposed product layer is unknown at each measurement step. When each of a plurality of product layers has been measured, and a scatterometry object is placed at the top of the layers, only the degrees of freedom of that scatterometry object should be unknown and only the profile of the object should need to be measured.

Abstract: The present invention provides a method for forming a substrate for use in calibrating a metrology tool in order to compensate for orientation-dependent variations within the metrology tool.

Abstract: A method is provided wherein a lithographic projection apparatus is used to print a series of test patterns on a test substrate to measure printed critical dimension as function of exposure dose setting and focus setting. A full-substrate analysis of measured critical dimension data is modeled by a response model of critical dimension. The response model includes an additive term which expresses a spatial variability of the response with respect to the surface of the test substrate. The method further includes fitting the model by fitting model parameters using measured critical dimension data, and controlling critical dimension using the fitted model.

Abstract: A method is provided for determining an actual profile of an object printed on a substrate. The method can include receiving an actual spectrum signal associated with the object, selecting a first model profile, and generating a first model spectrum signal associated with the first model profile. The method can further include comparing the first model spectrum signal with the actual spectrum signal. If the first model spectrum signal and the actual spectrum signal do not match a desired tolerance, the aforementioned selecting, generating, and comparing can be repeated with a second model profile. The second model profile can be selected based on the first model spectrum signal having undergone an optimization process based on a number of variable parameters of the first model profile, where the number of variable parameters is reduced by approximating the first model profile to a single shape with a reduced number of variable parameters.

Abstract: In a method for determining a structure parameter of a target pattern, a first series of calibration spectra are determined from at least one reference pattern, each spectra being determined using a different known value of at least one structure parameter of the respective reference pattern. The first series of calibration spectra does not take into account parameters of an apparatus used to produce the reference pattern. A representation of each of the first series calibration spectra is stored in a central library. A second series of calibration spectra corresponding to at least one of the stored spectra for a target spectrum is determined using the parameters of the apparatus for measuring the target spectrum. A measured target spectrum is produced by directing a beam of radiation onto the target pattern. The measured target spectrum and the second series of calibration spectra are compared, where this comparison is used to derive a value for the structure parameter of the target pattern.

Abstract: In target shape reconstruction, in order to determine efficiently and quickly the profile of complex targets on a substrate, the various degrees of freedom or variable parameters of the various shapes of which a single profile is made up can be reduced by linking together the variable parameters using simple formulae or by approximating the shape of the overall profile such that it takes in to account the various shapes making up that profile. Fewer parameters gives rise to fewer iterations of calculations on those parameters, which increases the speed of profile reconstruction.

Abstract: One or more focus settings for use in a device manufacturing method is determined by printing a plurality of target markers at different focus settings and using a scatterometer, e.g. off-line, to measure a property of the target markers that is indicative of focus.

Abstract: An overlay target on a substrate is disclosed, the overlay target including a periodic array of structures wherein every nth structure is different from the rest of the structures. The periodic array is desirably made of two interlaced gratings, one of the gratings having a different pitch from the other grating in order to create an asymmetry in the array. This asymmetry can then be measured by measuring the diffraction spectra of radiation reflected from the overlay target. Variation in the asymmetry indicates the presence of an overlay error in layers on the substrate, where overlay targets are printed on subsequent layers.

Abstract: A lithographic apparatus includes an illuminator configured to condition a beam of radiation and a support configured to hold a patterning device. The patterning device is configured to pattern the beam of radiation according to a desired pattern. The lithographic apparatus also includes a substrate table configured to hold a substrate and a projection system configured to project the patterned beam onto a target portion of the substrate to form a patterned image on the substrate. The apparatus further includes a sensor configured and arranged to intercept a portion of the beam and to measure a transmission of the beam through at least a portion of the patterning device.

Abstract: The present invention provides a method for forming a substrate for use in calibrating a metrology tool in order to compensate for orientation-dependent variations within the metrology tool.

Abstract: Building of a model profile for a target is disclosed. An embodiment of the method includes importing an image of a known object and superimposing, on this image, either by hand or automatically, an estimated profile. The estimated profile is defined mathematically and adjusted segment by segment in order to match the image such that the adjusted estimated profile may be stored alongside a diffraction spectrum associated with the image. Alternatively or additionally, a user may trace (or free-draw) the profile of a known image and subsequently map a shape-definer of a mathematical function such as a polynomial equation, a spline or a vector onto the estimated profile in order to obtain a profile and one or more variables of that profile that may be used to reconstruct the profile of an unknown object from its diffraction pattern.

Abstract: Measurement of a profile of a scatterometry object on top of one or more product layers on a substrate is disclosed. To prevent an unknown parameters of one or more product layers having an effect on the measurement of the object profile, the thickness of the one or more product layers is measured prior to measuring the profile of the scatterometry object on the layer(s). In an embodiment, each of a plurality of product layers is measured as it is exposed so that only the degree of freedom of the most recently exposed product layer is unknown at each measurement step. When each of a plurality of product layers has been measured, and a scatterometry object is placed at the top of the layers, only the degrees of freedom of that scatterometry object should be unknown and only the profile of the object should need to be measured.

Abstract: In a scatterometric method, a roughness value can be obtained by using a model including a surface layer having a variable parameter relating to its refractive index.

Abstract: In a scatterometric method, different targets with different sensitivities to a parameter of interest are printed in a calibration matrix and different spectra obtained. Principal component analysis is applied to the different spectra to obtain a calibration function that is less sensitive to variation in the underlying structure than a calibration function obtained from spectra obtained from a single target.

Abstract: In target shape reconstruction, in order to determine efficiently and quickly the profile of complex targets on a substrate, the various degrees of freedom or variable parameters of the various shapes of which a single profile is made up can be reduced by linking together the variable parameters using simple formulae or by approximating the shape of the overall profile such that it takes in to account the various shapes making up that profile. Fewer parameters gives rise to fewer iterations of calculations on those parameters, which increases the speed of profile reconstruction.