Abstract: An overlay metrology system may include a controller to generate optical tool error adjustments for a hybrid overlay target including optically-resolvable features and device-scale features by measuring a difference between an optical overlay measurement based on the optically-resolvable features and a device-scale overlay measurement based on the device-scale features, generate target-to-device adjustments for the hybrid overlay target based on positions of features within the device area, determine device-relevant overlay measurements for one or more locations in the device area based on at least one of the optical overlay measurement, the optical tool error adjustments, or the target-to-device adjustments, and provide overlay correctables for the device area to a lithography tool to modify exposure conditions for at least one subsequent exposure based on the device-relevant overlay measurements.

Abstract: Systems and method are presented for identifying process variations during manufacture of products such as semiconductor wafers. At a predetermined stage during manufacture of a first products, images of an area of the first product are obtained using different values of at least one imaging parameter. The images are then analyzed to generate a first contrast signature for said first product indicating variations of contrast with said at least one imaging parameter. At the same predetermined stage during manufacture of a second product, images of an area of said second product are obtained corresponding to said area of said first product using different values of said at least one imaging parameter. The images are analyzed to generate a second contrast signature for said second product indicating variations of contrast with said at least one imaging parameter.

Abstract: Metrology systems and methods are provided, which derive metrology target position on the wafer and possibly the target focus position during the movement of the wafer on the system's stage. The positioning data is derived before the target arrives its position (on-the-fly), sparing the time required in the prior art for the acquisition stage and increasing the throughput of the systems and methods. The collection channel may be split to provide for an additional moving-imaging channel comprising at least one TDI (time delay and integration) sensor with an associated analysis unit configured to derive wafer surface information, positioning and/or focusing information of the metrology targets with respect to the objective lens, during wafer positioning movements towards the metrology targets. Additional focusing-during-movement module and possibly feedbacking derived position and/or focus information to the stage may enhance the accuracy of the stopping of the stage.

Abstract: Focusing methods and modules are provided for metrology tools and systems. Methods comprise capturing image(s) of at least two layers of a ROI in an imaging target, binning the captured image(s), deriving a focus shift from the binned captured image(s) by comparing the layers, and calculating a focus position from the derived focus shift. Disclosed methods are direct, may be carried out in parallel to a part of the overlay measurement process and provide fast and simple focus measurements that improve metrology performance.

Abstract: An overlay metrology system includes a particle-beam metrology tool to scan a particle beam across an overlay target on a sample including a first-layer target element and a second-layer target element. The overlay metrology system may further include a controller to receive a scan signal from the particle-beam metrology tool, determine symmetry measurements for the scan signal with respect to symmetry metrics, and generate an overlay measurement between the first layer and the second layer based on the symmetry measurements in which an asymmetry of the scan signal is indicative of a misalignment of the second-layer target element with respect to the first-layer target element and a value of the overlay measurement is based on the symmetry measurements.

Abstract: An overlay metrology system may measure a first-layer pattern placement distance between a pattern of device features and a pattern of reference features on a first layer of an overlay target on a sample. The system may further measure, subsequent to fabricating a second layer including at least the pattern of device features and the pattern of reference features, a second-layer pattern placement distance between the pattern of device features and the pattern of reference features on the second layer. The system may further measure a reference overlay based on relative positions of the pattern of reference features on the first layer and the second layer. The system may further determine a device-relevant overlay for the pattern of device-scale features by adjusting the reference overlay with a difference between the first-layer pattern placement distance and the second-layer pattern placement distance.

Abstract: Metrology targets designs, design methods and measurement methods are provided, which reduce noise and enhance measurement accuracy. Disclosed targets comprise an additional periodic structure which is orthogonal to the measurement direction along which given target structures are periodic. For example, in addition to two or more periodic structures along each measurement direction in imaging or scatterometry targets, a third, orthogonal periodic structure may be introduced, which provides additional information in the orthogonal direction, can be used to reduce noise, enhances accuracy and enables the application of machine learning algorithms to further enhance accuracy. Signals may be analyzed slice-wise with respect to the orthogonal periodic structure, which can be integrated in a process compatible manner in both imaging and scatterometry targets.

Abstract: Systems and methods are provided, which calculate overlay misregistration error estimations from analyzed measurements of each ROI (region of interest) in at least one metrology imaging target, and incorporate the calculated overlay misregistration error estimations in a corresponding estimation of overlay misregistration. Disclosed embodiments provide a graduated and weighted analysis of target quality which may be integrated in a continuous manner into the metrology measurement processes, and moreover evaluates target quality in terms of overlay misregistration, which forms a common basis for evaluation of errors from different sources, such as characteristics of production steps, measurement parameters and target characteristics.

Abstract: Focus metrology methods and modules are provided, which use aerial-images-based transformations to share measurement information derived from multiple targets and/or to design additional targets to specified compliant targets, which enable simple adjustment of focus targets to changing production conditions. Methods comprise positioning two or more focus targets in each wafer field, conducting focus measurements of the targets, transforming the focus measurements into a single set of results for each field, using a transformation between the targets that is based on the aerial images thereof, and deriving focus results from the single sets of results; and possibly designing the focus targets from specified targets using aerial image parameters of the specified targets.

Abstract: Systems and method are presented for identifying process variations during manufacture of products such as semiconductor wafers. At a predetermined stage during manufacture of a first products, images of an area of the first product are obtained using different values of at least one imaging parameter. The images are then analyzed to generate a first contrast signature for said first product indicating variations of contrast with said at least one imaging parameter. At the same predetermined stage during manufacture of a second product, images of an area of said second product are obtained corresponding to said area of said first product using different values of said at least one imaging parameter. The images are analyzed to generate a second contrast signature for said second product indicating variations of contrast with said at least one imaging parameter.

Abstract: A method of overlay control in silicon wafer manufacturing comprises firstly locating a target comprising a diffraction grating on a wafer layer; and then measuring the alignment of patterns in successive layers of the wafer. The location of the target may be done by the pupil camera rather than a vision camera by scanning the target to obtain pupil images at different locations along a first axis. The pupil images may comprise a first order diffraction pattern for each location. A measurement of signal intensity in the first order diffraction pattern is then obtained for each location. The variation of signal intensity with location along each axis is then analyzed to calculate the location of a feature in the target.

Abstract: A system for generating and implementing programmed defects includes a lithography tool configured to form a multi-pattern structure including a first array pattern and a second array pattern on a sample. The first array pattern or the second array pattern contains a programmed defect to differentiate the first array pattern from the second array pattern. The system includes a metrology tool configured to acquire one or more images of the first array pattern and the second array pattern having a field-of-view containing the programmed defect. The system includes a controller including one or more processors. The one or more processors are configured to receive the images of the first array pattern and the second array pattern from the metrology, and determine a metrology parameter associated with the first array pattern or the second array pattern.

Abstract: Target designs and methods are provided, which relate to periodic structures having elements recurring with a first pitch in a first direction. The elements are periodic with a second pitch along a second direction that is perpendicular to the first direction and are characterized in the second direction by alternating, focus-sensitive and focus-insensitive patterns with the second pitch. In the produced targets, the first pitch may be about the device pitch and the second pitch may be several times larger. The first, focus-insensitive pattern may be produced to yield a first critical dimension and the second, focus-sensitive pattern may be produced to yield a second critical dimension that may be equal to the first critical dimension only when specified focus requirements are satisfied, or provide scatterometry measurements of zeroth as well as first diffraction orders, based on the longer pitch along the perpendicular direction.

Abstract: A method is provided that comprises printing FEM wafers having different predefined focus offsets and multiple corresponding sites, measuring signals from the sites, and quantifying a focus inaccuracy by comparing the measured signals from the corresponding sites across the wafers.

Abstract: Focus metrology methods and modules are provided, which use aerial-images-based transformations to share measurement information derived from multiple targets and/or to design additional targets to specified compliant targets, which enable simple adjustment of focus targets to changing production conditions. Methods comprise positioning two or more focus targets in each wafer field, conducting focus measurements of the targets, transforming the focus measurements into a single set of results for each field, using a transformation between the targets that is based on the aerial images thereof, and deriving focus results from the single sets of results; and possibly designing the focus targets from specified targets using aerial image parameters of the specified targets.

Abstract: Target designs and methods are provided, which relate to periodic structures having elements recurring with a first pitch in a first direction. The elements are periodic with a second pitch along a second direction that is perpendicular to the first direction and are characterized in the second direction by alternating, focus-sensitive and focus-insensitive patterns with the second pitch. In the produced targets, the first pitch may be about the device pitch and the second pitch may be several times larger. The first, focus-insensitive pattern may be produced to yield a first critical dimension and the second, focus-sensitive pattern may be produced to yield a second critical dimension that may be equal to the first critical dimension only when specified focus requirements are satisfied, or provide scatterometry measurements of zeroth as well as first diffraction orders, based on the longer pitch along the perpendicular direction.