Abstract: Metrology tools and methods are provided, which estimate the effect of topographic phases corresponding to different diffraction orders, which result from light scattering on periodic targets, and adjust the measurement conditions to improve measurement accuracy. In imaging, overlay error magnification may be reduced by choosing appropriate measurement conditions based on analysis of contrast function behavior, changing illumination conditions (reducing spectrum width and illumination NA), using polarizing targets and/or optical systems, using multiple defocusing positions etc. On-the-fly calibration of measurement results may be carried out in imaging or scatterometry using additional measurements or additional target cells.

Abstract: Resistivity probes can be used to test integrated circuits. In one example, a resistivity probe has a substrate with multiple vias and multiple metal pins. Each of the metal pins is disposed in one of the vias. The metal pins extend out of the substrate. Interconnects provide an electrical connection to the metal pins. In another example, a resistivity probe has a substrate with a top surface and multiple elements extending from the substrate. Each of the elements curves from the substrate to a tip of the element such that each of the elements is non-parallel to the top surface of the substrate.

Abstract: Disclosed are apparatus and methods for inspecting a semiconductor sample. Locations corresponding to candidate defect events on a semiconductor sample are provided from an optical inspector operable to acquire optical images from which such candidate defect events are detected at their corresponding locations across the sample. High-resolution images are acquired from a high-resolution inspector of the candidate defect events at their corresponding locations on the sample. Each of a set of modelled optical images, which have been modeled from a set of the acquired high-resolution images, is correlated with corresponding ones of a set of the acquired optical images, to identify surface noise events, as shown in the set of high-resolution images, as sources for the corresponding candidate events in the set of acquired optical images. Otherwise, a subsurface event is identified as a likely source for a corresponding candidate defect event.

Abstract: Systems and methods for providing improved measurements and predictions of geometry induced overlay errors are disclosed. Information regarding variations of overlay errors is obtained and analyzed to improve semiconductor processes as well as lithography patterning. In some embodiments, a cascading analysis process is utilized to breakdown the wafer geometry induced overlay into various components. The breakdown analysis may also be utilized to determine effectiveness factors for the various components, which in turn may improve the prediction accuracy of the impact of wafer geometry on wafer overlay. Furthermore, the measurements and/or predictions of the wafer geometry induced overlay errors may be utilized to provide overlay monitoring and correction solutions.

Abstract: Disclosed are apparatus and methods for characterizing a plurality of structures of interest on a semiconductor wafer. A plurality of spectra signals are measured from a particular structure of interest at a plurality of azimuth angles from one or more sensors of a metrology system. A difference spectrum is determined based on the spectra signals obtained for the azimuth angles. A quality indication of the particular structure of interest is determined and reported based on analyzing the difference spectrum.

Abstract: Methods and systems for evaluating and ranking the measurement efficacy of multiple sets of measurement system combinations and recipes for a particular metrology application are presented herein. Measurement efficacy is based on estimates of measurement precision, measurement accuracy, correlation to a reference measurement, measurement time, or any combination thereof. The automated the selection of measurement system combinations and recipes reduces time to measurement and improves measurement results. Measurement efficacy is quantified by a set of measurement performance metrics associated with each measurement system and recipe. In one example, the sets of measurement system combinations and recipes most capable of measuring the desired parameter of interest are presented to the user in rank order based on corresponding values of one or more measurement performance metrics. A user is able to select the appropriate measurement system combination in an objective, quantitative manner.

Abstract: Methods and systems for building and using a parameter isolation model to isolate measurement signal information associated with a parameter of interest from measurement signal information associated with incidental model parameters are presented herein. The parameter isolation model is trained by mapping measurement signals associated with a first set of instances of a metrology target having known values of a plurality of incidental model parameters and known values of a parameter of interest to measurement signals associated with a second set of instances of the metrology target having nominal values of the plurality of incidental model parameters and the known values of the parameter of interest. The trained parameter isolation model receives raw measurement signals and isolates measurement signal information associated with a specific parameter of interest for model-based parameter estimation.

Abstract: Methods and systems for measuring process induced errors in a multiple patterning semiconductor fabrication process based on measurements of a specimen and process information from one or more previous process steps employed to fabricate the specimen are presented herein. A metrology tool is employed after a number of process steps have been executed. The metrology tool measures structural parameters of interest of metrology targets on the wafer based on measured signals and process information, and communicates correctable process parameter values to one or more process tools involved in the previous process steps. When executed by the appropriate process tool, the correctable process parameter values reduce process induced errors in the geometry of the structures fabricated by the process flow. In another aspect, multiple metrology tools are used to control a fabrication process in combination with process information from one or more process steps in the process flow.

Abstract: Techniques are provided that can select defects based on criticality of design pattern as well as defect attributes for process window qualification (PWQ). Defects are sorted into categories based on process conditions and similarity of design. Shape based grouping can be performed on the random defects. Highest design based grouping scores can be assigned to the bins, which are then sorted. Particular defects can be selected from the bins. These defects may be reviewed.

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: Noise reduction in a difference image of an optical inspection tool is provided by calculating a difference image across layers of a multi-layered wafer. A first wafer image of a first wafer layer and a second wafer image of a second wafer layer are used. The first wafer image and the second wafer image are at a same planar location on the multi-layered wafer, but of different layers and/or after different process steps. A first difference image is calculated between the first wafer image and the second wafer image to reduce wafer noise. Defects can be identified using the first difference image. A system with an image data acquisition subsystem can be used to perform this technique.

Abstract: A DUV laser includes an optical bandwidth filtering device, such as etalon, which is disposed outside of the laser oscillator cavity of the fundamental laser, and which directs one range of wavelengths into one portion of a frequency conversion chain and another range of wavelengths into another portion of the frequency conversion train, thereby reducing the bandwidth of the DUV laser output while maintaining high conversion efficiency in the frequency conversion chain.

Abstract: A system includes a beam steering assembly configured to adjust an incident beam to form a corrected beam; a beam monitoring assembly configured to generate monitoring data for the corrected beam including one or more offset parameters of the corrected beam; and a controller configured to store one or more zero parameters of the corrected beam, calculate at least one difference between the one or more zero parameters and the one or more offset parameters of the corrected beam, determine one or more beam position adjustments of the incident beam based on the at least one difference between the one or more zero parameters and the one or more offset parameters of the corrected beam, and direct the beam steering assembly via one or more motor drivers to actuate one or more motors to adjust the incident beam to form the corrected beam.

Abstract: A metrology system includes a controller communicatively coupled to a metrology tool. The controller may generate a three-dimensional model of a sample, generate a predicted metrology image corresponding to a predicted analysis of the sample with the metrology tool based on the three-dimensional model, evaluate two or more candidate metrology recipes for extracting the metrology measurement from the one or more predicted metrology images, select, based on one or more selection metrics, a metrology recipe from the two or more candidate metrology recipes for extracting a metrology measurement from an image of the structure from the metrology tool, receive an output metrology image of a fabricated structure from the metrology tool based on a metrology measurement of the fabricated structure, and extract the metrology measurement associated with the fabricated structure from the output metrology image based on the metrology recipe.

Abstract: A broadband illumination source is disclosed. The broadband illumination source may include a pump source configured to generate pump illumination. The broadband illumination also includes an active medium containing nanocrystals. The broadband illumination source includes pump illumination optics configured to direct pump illumination into the active medium. The active medium is configured to emit broadband illumination by down-converting a portion of the pump illumination via photoluminescence.

Abstract: Disclosed are apparatus and methods for determining height of a semiconductor structure. The system includes an illumination module for directing one or more source lines or points towards a specimen having multiple surfaces at different relative heights and a collection module for detecting light reflected from the surfaces. The collection module contains at least two detectors with one slit or pinhole in front of each detector that that are positioned to receive light reflected from one of the surfaces. A first detector receives reflected light from a slit or pinhole that is positioned before a focal point, and a second detector receive reflected light from a slit or pinhole that is positioned after the focal point so that the first and second detector receive light having different intensity values unless the surface is at an optimum focus. The system includes a processor system for determining a height based on the detected light received by the detectors from two of the surfaces.

Abstract: Methods and systems for estimating values of parameters of interest based on repeated measurements of a wafer during a process interval are presented herein. In one aspect, one or more optical metrology subsystems are integrated with a process tool, such as an etch tool or a deposition tool. Values of one or more parameters of interest measured while the wafer is being processed are used to control the process itself. The measurements are performed quickly and with sufficient accuracy to enable yield improvement of a semiconductor fabrication process flow. In one aspect, values of one or more parameters of interest are estimated based on spectral measurements of wafers under process using a trained signal response metrology (SRM) measurement model. In another aspect, a trained signal decontamination model is employed to generate decontaminated optical spectra from measured optical spectra while the wafer is being processed.

Abstract: Disclosed are methods and apparatus for facilitating defect detection in a multilayer stack. The method includes selection of a set of structure parameters for modeling a particular multilayer stack and a particular defect contained within such particular multilayer stack and a set of operating parameters for an optical inspection system. Based on the set of structure and operating parameters, an electromagnetic simulation is performed of waves scattered from the particular multilayer stack and defect and arriving at a collection pupil of the optical inspection system.

Abstract: Methods and systems for calibrating the location of x-ray beam incidence onto a specimen in an x-ray scatterometry metrology system are described herein. The precise location of incidence of the illumination beam on the surface of the wafer is determined based on occlusion of the illumination beam by two or more occlusion elements. The center of the illumination beam is determined based on measured values of transmitted flux and a model of the interaction of the beam with each occlusion element. The position of the axis of rotation orienting a wafer over a range of angles of incidence is adjusted to align with the surface of wafer and intersect the illumination beam at the measurement location. A precise offset value between the normal angle of incidence of the illumination beam relative to the wafer surface and the zero angle of incidence as measured by the specimen positioning system is determined.

Abstract: Defect classification includes acquiring one or more images of a specimen, receiving a manual classification of one or more training defects based on one or more attributes of the one or more training defects, generating an ensemble learning classifier based on the received manual classification and the attributes of the one or more training defects, generating a confidence threshold for each defect type of the one or more training defects based on a received classification purity requirement, acquiring one or more images including one or more test defects, classifying the one or more test defects with the generated ensemble learning classifier, calculating a confidence level for each of the one or more test defects with the generated ensemble learning classifier and reporting one or more test defects having a confidence level below the generated confidence threshold via the user interface device for manual classification.