Patent application number | Description | Published |
20080266561 | OPTICAL GAIN APPROACH FOR ENHANCEMENT OF OVERLAY AND ALIGNMENT SYSTEMS PERFORMANCE - A resultant image of a grating target may be obtained by dividing an image of the target into first and second portions and optically modifying the first and/or second portion such that a final image formed from their combination is characterized by a Moiré pattern. The resultant image may be analyzed to determine a shift in the grating target from a shift in the Moiré pattern. Optical alignment apparatus may include a first beam splitter, an image transformation element optically coupled to the first beam splitter, and a second beam splitter. The first beam splitter divides an image of a grating target into first and second portions. The second beam splitter combines the first portion and the second portion. The image transformation element optically modifies the first and/or second portion such that a final image formed from their combination is characterized by a Moiré pattern. | 10-30-2008 |
20090279091 | TARGET DESIGN AND METHODS FOR SCATTEROMETRY OVERLAY DETERMINATION - Disclosed are methods and apparatus for determining overlay error. Radiation that is scattered from each of a plurality of cells of a target is measured. Each cell includes at least a first grating structure formed by a first process and a second grating structure formed by a second process and wherein each cell has a predefined offset between such each cell's first and second grating structures. The first and second grating structures of the different cells have different predefined offsets, and each predefined offset of each cell is selected to cause one or more terms to be cancelled from a periodic function that represents radiation scattered and measured from each cell. The scattered radiation of each cell is represented with a periodic function having a plurality of unknowns parameters, including an unknown overlay error, and the unknown overlay error is determined based on the plurality of periodic functions for the plurality of cells. | 11-12-2009 |
20100175033 | SCATTEROMETRY METROLOGY TARGET DESIGN OPTIMIZATION - A metrology target design may be optimized using inputs including metrology target design information, substrate information, process information, and metrology system information. Acquisition of a metrology signal with a metrology system may be modeled using the inputs to generate one or more optical characteristics of the metrology target. A metrology algorithm may be applied to the characteristics to determine a predicted accuracy and precision of measurements of the metrology target made by the metrology system. Part of the information relating to the metrology target design may be modified and the signal modeling and metrology algorithm may be repeated to optimize the accuracy and precision of the one or more measurements. The metrology target design may be displayed or stored after the accuracy and precision are optimized. | 07-08-2010 |
20110051116 | Substrate Matrix To Decouple Tool And Process Effects - A method of characterizing a process by selecting the process to characterize, selecting a parameter of the process to characterize, determining values of the parameter to use in a test matrix, specifying an eccentricity for the test matrix, selecting test structures to be created in cells on a substrate, processing the substrate through the process using in each cell the value of the parameter as determined by the eccentric test matrix, measuring a property of the test structures in the cells, and developing a correlation between the parameter and the property. | 03-03-2011 |
20110069312 | METROLOGY SYSTEMS AND METHODS - Various metrology systems and methods are provided. | 03-24-2011 |
20110202298 | METHOD AND SYSTEM FOR PROVIDING PROCESS TOOL CORRECTABLES USING AN OPTIMIZED SAMPLING SCHEME WITH SMART INTERPOLATION - The present invention may include performing a first measurement on a wafer of a first lot of wafers via an omniscient sampling process, calculating a first set of process tool correctables utilizing one or more results of the measurement performed via an omniscient sampling process, randomly selecting a set of field sampling locations of the wafer of a first lot of wafers, calculating a second set of process tool correctables by applying an interpolation process to the randomly selected set of field sampling locations, wherein the interpolation process utilizes values from the first set of process tool correctables for the randomly selected set of field sampling locations in order to calculate correctables for fields of the wafer of the first lot not included in the set of randomly selected fields, and determining a sub-sampling scheme by comparing the first set of process tool correctables to the second set of correctables. | 08-18-2011 |
20110310388 | DISCRETE POLARIZATION SCATTEROMETRY - Systems and methods for discrete polarization scatterometry are provided. | 12-22-2011 |
20120022679 | ADVANCED PROCESS CONTROL OPTIMIZATION - A method for automatic process control (APC) performance monitoring may include, but is not limited to: computing one or more APC performance indicators for one or more production lots of semiconductor devices; and displaying a mapping of the one or more APC performance indicators to the one or more production lots of semiconductor devices. | 01-26-2012 |
20120033215 | MULTI-LAYER OVERLAY METROLOGY TARGET AND COMPLIMENTARY OVERLAY METROLOGY MEASUREMENT SYSTEMS - A multi-layer overlay target for use in imaging based metrology is disclosed. The overlay target includes a plurality of target structures including three or more target structures, each target structure including a set of two or more pattern elements, wherein the target structures are configured to share a common center of symmetry upon alignment of the target structures, each target structure being invariant to N degree rotation about the common center of symmetry, wherein N is equal to or greater than 180 degrees, wherein each of the two or more pattern elements has an individual center of symmetry, wherein each of the two or more pattern elements of each target structure is invariant to M degree rotation about the individual center of symmetry, wherein M is equal to or greater than 180 degrees. | 02-09-2012 |
20120033226 | OPTICS SYMMETRIZATION FOR METROLOGY - The present invention includes an illumination source, at least one illumination symmetrization module (ISM) configured to symmetrize at least a portion of light emanating from the illumination source, a first beam splitter configured to direct a first portion of light processed by the ISM along an object path to a surface of one or more specimens and a second portion of light processed by the ISM along a reference path, and a detector disposed along a primary optical axis, wherein the detector is configured to collect a portion of light reflected from the surface of the one or more specimens. | 02-09-2012 |
20120120396 | ANGLE-RESOLVED ANTISYMMETRIC SCATTEROMETRY - A method for determining an overlay offset may include, but is not limited to: obtaining a first anti-symmetric differential signal (ΔS | 05-17-2012 |
20120206729 | STRUCTURED ILLUMINATION FOR CONTRAST ENHANCEMENT IN OVERLAY METROLOGY - Contrast enhancement in a metrology tool may include generating a beam of illumination, directing a portion of the generated beam onto a surface of a spatial light modulator (SLM), directing at least a portion of the generated beam incident on the surface of the SLM through an aperture of an aperture stop and onto one or more target structures of one or more samples, and generating a selected illumination pupil function of the illumination transmitted through the aperture utilizing the SLM in order to establish a contrast level of one or more field images of the one or more target structures above a selected contrast threshold, and performing one or more metrology measurements on the one or more target structures utilizing the selected illumination pupil function. | 08-16-2012 |
20130035888 | METHOD AND SYSTEM FOR PROVIDING A QUALITY METRIC FOR IMPROVED PROCESS CONTROL - The present invention may include acquiring a plurality of overlay metrology measurement signals from a plurality of metrology targets distributed across one or more fields of a wafer of a lot of wafers, determining a plurality of overlay estimates for each of the plurality of overlay metrology measurement signals using a plurality of overlay algorithms, generating a plurality of overlay estimate distributions, and generating a first plurality of quality metrics utilizing the generated plurality of overlay estimate distributions, wherein each quality metric corresponds with one overlay estimate distribution of the generated plurality of overlay estimate distributions, each quality metric a function of a width of a corresponding generated overlay estimate distribution, each quality metric further being a function of asymmetry present in an overlay metrology measurement signal from an associated metrology target. | 02-07-2013 |
20130044331 | OVERLAY METROLOGY BY PUPIL PHASE ANALYSIS - The present invention may include measuring a first phase distribution across a pupil plane of a portion of illumination reflected from a first overlay target of a semiconductor wafer, wherein the first overlay target is fabricated to have a first intentional overlay, measuring a second phase distribution across the pupil plane of a portion of illumination reflected from a second overlay target, wherein the second overlay target is fabricated to have a second intentional overlay in a direction opposite to and having the same magnitude as the first intentional overlay, determining a first phase tilt associated with a sum of the first and second phase distributions, determining a second phase tilt associated with a difference between the first and second phase distributions, calibrating a set of phase tilt data, and determining a test overlay value associated with the first and second overlay target. | 02-21-2013 |
20130229661 | Metrology Systems and Methods - Various metrology systems and methods are provided. One metrology system includes a light source configured to produce a diffraction-limited light beam, an apodizer configured to shape the light beam in the entrance pupil of illumination optics, and optical elements configured to direct the diffraction-limited light beam from the apodizer to an illumination spot on a grating target on a wafer and to collect scattered light from the grating target. The metrology system further includes a field stop and a detector configured to detect the scattered light that passes through the field stop. In addition, the metrology system includes a computer system configured to determine a characteristic of the grating target using output of the detector. | 09-05-2013 |
20130342831 | DEVICE-LIKE SCATTEROMETRY OVERLAY TARGETS - In one embodiment, a semiconductor target for detecting overlay error between two or more successive layers of a substrate or between two or more separately generated patterns on a single layer of a substrate is disclosed. The target comprises at least a plurality of a plurality of first grating structures having a course pitch that is resolvable by an inspection tool and a plurality of second grating structures positioned relative to the first grating structures. The second grating structures have a fine pitch that is smaller than the course pitch, and the first and second grating structures are both formed in two or more successive layers of a substrate or between two or more separately generated patterns on a single layer of a substrate. The first and second gratings have feature dimensions that all comply with a predefined design rules specification. | 12-26-2013 |
20140065736 | DEVICE CORRELATED METROLOGY (DCM) FOR OVL WITH EMBEDDED SEM STRUCTURE OVERLAY TARGETS - Aspects of the present disclosure describe a target for use in measuring a relative position between two substantially coplanar layers of a device. The target includes periodic structures in first and second layers. Differences in relative position of the first and the second layers between the first and second periodic structures and the respective device-like structure can be measured to correct the relative position of the first and the second layers between the first and second periodic structures. It is emphasized that this abstract is provided to comply with the rules requiring an abstract that will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. | 03-06-2014 |
20140111791 | PHASE CHARACTERIZATION OF TARGETS - Systems and methods are provided which derive target characteristics from interferometry images taken at multiple phase differences between target beams and reference beams yielding the interferometry images. The illumination of the target and the reference has a coherence length of less than 30 microns to enable scanning the phase through the coherence length of the illumination. The interferometry images are taken at the pupil plane and/or in the field plane to combine angular and spectroscopic scatterometry data that characterize and correct target topography and enhance the performance of metrology systems. | 04-24-2014 |
20140141536 | Method and System for Providing a Target Design Displaying High Sensitivity to Scanner Focus Change - A segmented mask includes a set of cell structures, wherein each cell structure includes a set of features having an unresolvable segmentation pitch along a first direction, wherein the unresolvable segmentation pitch along the first direction is smaller than the illumination of the lithography printing tool, wherein the plurality of cell structures have a pitch along a second direction perpendicular to the first direction, wherein the unresolvable segmentation pitch is suitable for generating a printed pattern for shifting the best focus position of the lithography tool by a selected amount to achieve a selected level of focus sensitivity. | 05-22-2014 |
20140146322 | Apodization for Pupil Imaging Scatterometry - The disclosure is directed to various apodization schemes for pupil imaging scatterometry. In some embodiments, the system includes an apodizer disposed within a pupil plane of the illumination path. In some embodiments, the system further includes an illumination scanner configured to scan a surface of the sample with at least a portion of apodized illumination. In some embodiments, the system includes an apodized pupil configured to provide a quadrupole illumination function. In some embodiments, the system further includes an apodized collection field stop. The various embodiments described herein may be combined to achieve certain advantages. | 05-29-2014 |
20140240951 | Systems for Providing Illumination in Optical Metrology - The disclosure is directed to systems for providing illumination to a measurement head for optical metrology. In some embodiments of the disclosure, illumination beams from a plurality of illumination sources are combined to deliver illumination at one or more selected wavelengths to the measurement head. In some embodiments of the disclosure, intensity and/or spatial coherence of illumination delivered to the measurement head is controlled. In some embodiments of the disclosure, illumination at one or more selected wavelengths is delivered from a broadband illumination source configured for providing illumination at a continuous range of wavelengths. | 08-28-2014 |
20140316730 | ON-DEVICE METROLOGY - Methods and systems for performing semiconductor metrology directly on device structures are presented. A measurement model is created based on measured training data collected from at least one device structure. The trained measurement model is used to calculate process parameter values, structure parameter values, or both, directly from measurement data collected from device structures of other wafers. In some examples, measurement data from multiple targets is collected for model building, training, and measurement. In some examples, the use of measurement data associated with multiple targets eliminates, or significantly reduces, the effect of under layers in the measurement result, and enables more accurate measurements. Measurement data collected for model building, training, and measurement may be derived from measurements performed by a combination of multiple, different measurement techniques. | 10-23-2014 |
20150036142 | Metrology Systems and Methods - Various metrology systems and methods are provided. One metrology system includes a light source configured to produce a diffraction-limited light beam, an apodizer configured to shape the light beam in the entrance pupil of illumination optics, and optical elements configured to direct the diffraction-limited light beam from the apodizer to an illumination spot on a grating target on a wafer and to collect scattered light from the grating target. The metrology system further includes a field stop and a detector configured to detect the scattered light that passes through the field stop. In addition, the metrology system includes a computer system configured to determine a characteristic of the grating target using output of the detector. | 02-05-2015 |
20150116717 | SCANNING IN ANGLE-RESOLVED REFLECTOMETRY AND ALGORITHMICALLY ELIMINATING DIFFRACTION FROM OPTICAL METROLOGY - Angle-resolved reflectometers and reflectometry methods are provided, which comprise a coherent light source, an optical system arranged to scan a test pattern using a spot of coherent light from the light source to yield realizations of the light distribution in the collected pupil, wherein the spot covers a part of the test pattern and the scanning is carried out optically or mechanically according to a scanning pattern, and a processing unit arranged to generate a composite image of the collected pupil distribution by combining the pupil images. Metrology systems and methods are provided, which reduce diffraction errors by estimating, quantitatively, a functional dependency of measurement parameters on aperture sizes and deriving, from identified diffraction components of the functional dependency which relate to the aperture sizes, correction terms for the measurement parameters with respect to the measurement conditions. | 04-30-2015 |
20150177162 | Angle-Resolved Antisymmetric Scatterometry - A method for determining an overlay offset may include, but is not limited to: obtaining a first anti-symmetric differential signal (ΔS | 06-25-2015 |
20150198524 | NEAR FIELD METROLOGY - Metrology systems and methods are provided herein, which comprise an optical element that is positioned between an objective lens of the system and a target. The optical element is arranged to enhance evanescent modes of radiation reflected by the target. Various configurations are disclosed: the optical element may comprise a solid immersion lens, a combination of Moiré-elements and solid immersion optics, dielectric-metal-dielectric stacks of different designs, and resonating elements to amplify the evanescent modes of illuminating radiation. The metrology systems and methods are configurable to various metrology types, including imaging and scatterometry methods. | 07-16-2015 |
20150204664 | SYMMETRIC TARGET DESIGN IN SCATTEROMETRY OVERLAY METROLOGY - Metrology methods, systems and targets are provided, which implement a side by side paradigm. Adjacent cells with periodic structures are used to extract the overlay error, e.g., by introducing controllable phase shifts or image shifts which enable algorithmic computation of the overlay. The periodic structures are designed to exhibit a rotational symmetry to support the computation and reduce errors. | 07-23-2015 |
20150219449 | REFLECTION SYMMETRIC SCATTEROMETRY OVERLAY TARGETS AND METHODS - A method for target measurement is provided which comprises designing a reflection-symmetric target and measuring overlays of the target along at least one reflection symmetry direction of the target. Also, a tool calibration method comprising calibrating a scatterometry measurement tool with respect to a reflection symmetry of a reflection symmetric target. Further provided are methods of measuring scatterometry overlay using first order and zeroth order scatterometry measurements of a reflection-symmetric scatterometry targets. Also, a scatterometry target comprising a reflection-symmetric target having two cells in each of at least two measurement directions, wherein respective cells have different offsets along one measurement direction and similar offsets along other measurement directions. Further, a scatterometry measurement system comprising a reflection symmetric illumination and calibrated to measure reflection symmetric targets. Also, metrology tool comprising an illumination path and a collection path of the tool which are symmetric to reflection symmetries of a target. | 08-06-2015 |
20150233705 | REDUCING ALGORITHMIC INACCURACY IN SCATTEROMETRY OVERLAY METROLOGY - Methods and systems for minimizing of algorithmic inaccuracy in scatterometry overlay (SCOL) metrology are provided. SCOL targets are designed to limit the number of oscillation frequencies in a functional dependency of a resulting SCOL signal on the offset and to reduce the effect of higher mode oscillation frequencies. The targets are segmented in a way that prevents constructive interference of high modes with significant amplitudes, and thus avoids the inaccuracy introduced by such terms into the SCOL signal. Computational methods remove residual errors in a semi-empirical iterative process of compensating for the residual errors algorithmically or through changes in target design. | 08-20-2015 |
20150309402 | TARGET ELEMENT TYPES FOR PROCESS PARAMETER METROLOGY - Metrology targets, target design methods and metrology methods are provided. Metrology targets comprise target elements belonging to two or more target element types. Each target element type comprises unresolved features which offset specified production parameters to a specified extent and thus provide sensitivity monitoring and optimization tools for process parameters such as focus and dose. | 10-29-2015 |
20150316783 | Apodization for Pupil Imaging Scatterometry - The disclosure is directed to various apodization schemes for pupil imaging scatterometry. In some embodiments, the system includes an apodizer disposed within a pupil plane of the illumination path. In some embodiments, the system further includes an illumination scanner configured to scan a surface of the sample with at least a portion of apodized illumination. In some embodiments, the system includes an apodized pupil configured to provide a quadrupole illumination function. In some embodiments, the system further includes an apodized collection field stop. The various embodiments described herein may be combined to achieve certain advantages. | 11-05-2015 |