Abstract: A first wafer is fabricated using a first value for a process parameter specifying a process condition in fabricating the structure. A first value of a dispersion is measured from the first wafer. A second wafer is fabricated using a second value for the process parameter. A second value of the dispersion is measured from the second wafer. A third wafer is fabricated using a third value for the process parameter. The first, second, and third values for the process parameter are different from each other. A third value of the dispersion is measured from the third wafer. A dispersion function is defined to relate the process parameter to the dispersion using the first, second, and third values for the process parameter and the measured first, second, and third values of the dispersion. The simulated diffraction signal is generated using the defined dispersion function. The simulated diffraction signal is stored.

Abstract: Provided is a system for determining profile parameters of a sample structure on a workpiece using an optical metrology system optimized to achieve one or more accuracy targets. The optical metrology system comprises an optical metrology tool configured to measure a diffraction signal off a sample structure, an optical metrology tool model configured to model the optical metrology tool using a selected number of rays and selected beam propagation parameters for the illumination beam and the diffraction beam; a signal adjuster configured to adjust the measured diffraction signal off the sample structure using the optical metrology tool model and calibration parameters, the signal adjuster generating an adjusted metrology output signal; and a profile extractor configured to determine one or more profile parameters of the sample structure using the adjusted metrology output signal, a profile model of the sample structure, and one or more extraction modules.

Abstract: Provided is a method for determining profile parameters of a sample structure on a workpiece using an optical metrology system optimized to achieve one or more accuracy targets, the optical metrology system including an optical metrology tool, an optical metrology tool model, a profile model of the sample structure, and a parameter extraction algorithm, the method comprising: setting one or more accuracy targets for profile parameter determination for the sample structure; selecting a number of rays and beam propagation parameters to be used to model the optical metrology tool, measuring a diffraction signal off the sample structure using the optical metrology tool, generating a metrology output signal, determining an adjusted metrology output signal using the metrology output signal and calibration data, concurrently optimizing the optical metrology tool model and the profile model using the adjusted metrology output signal and the parameter extraction algorithm.

Abstract: Provided is a method for controlling a fabrication cluster using an optical metrology system that includes an optical metrology tool, an optical metrology model, and a profile extraction algorithm. The method comprises: selecting a number of rays for the illumination beam, selecting beam propagation parameters, using a processor, determining beam propagation parameters from the light source of the to the sample structure, determining the beam propagation parameters from the sample structure to the detector, calculating intensity and polarization of each ray on the detector, generating a total intensity and polarization of the diffraction beam, calculating a metrology output signal from the total intensity and polarization, extracting the one or more profile parameters using the metrology output signal, transmitting at least one profile parameter to a fabrication cluster, and adjusting at least one process parameter or equipment setting of the fabrication cluster.

Abstract: Provided is a method for determining a profile of a sample structure on a workpiece using an optical metrology system that includes an optical metrology tool, an optical metrology model, and a profile extraction algorithm. The method comprises selecting a number of rays for the illumination beam, selecting beam propagation parameters, and using a processor, determining beam propagation parameters for each ray of the selected number of rays, determining the beam propagation parameters for each ray, calculating intensity and polarization of each ray, calculating total intensity and polarization of the diffraction beam, calculating a metrology output signal, extracting one or more profile parameters using the metrology output signal, calibration data, and a profile extraction algorithm.

Abstract: An improved procedure for calibrating the azimuth angle in a metrology module for use in a metrology system that is used for measuring a target on a wafer, and the metrology modules can include oblique Spectroscopic Ellipsometry (SE) and unpolarized or polarized spectroscopic reflectometer devices.

Abstract: Provided is a method of optimizing sensitivity of measurements of an optical metrology tool using two or more illumination beams directed to a structure on a workpiece comprising selecting target structures for measurement, obtaining diffraction signals off the selected structures as a function of angle of incidence for each illumination beam, determining a selected angle of incidence for each of the two or more illumination beams, setting sensitivity objectives for optical metrology measurements, developing a design for the optical metrology tool to achieve the corresponding selected angle of incidence of the two or more illumination beams, obtaining sensitivity data using the optical metrology tool, and if the sensitivity objectives are not met, adjusting the selection of target structures, the selected angle of incidence of the two or more illumination beams, the sensitivity objectives, and/or the design of the optical metrology tool, and iterating the developing of the design, obtaining sensitivity data,

Abstract: Provided is a method for determining one or more profile parameters of a structure using an optical metrology model, the optical metrology model including a profile model, an approximation diffraction model, and a fine diffraction model. A simulated approximation diffraction signal is generated based on an approximation diffraction model of the structure. A set of difference diffraction signals is obtained by subtracting the simulated approximation diffraction signal from each of simulated fine diffraction signals and paired with the corresponding profile parameters. A machine learning system is trained using the pairs of difference diffraction signal and corresponding profile parameters. A measured diffraction signal adjusted by the simulated approximation diffraction signal is input into the trained machine learning system and generates the corresponding profile parameters.

Abstract: A Pre-Aligned Metrology System comprising a number of Pre-Aligned Metrology Assemblies and Pre-Aligned Metrology Modules for measuring a target on a wafer. The Pre-Aligned Metrology Assemblies and Pre-Aligned Metrology Modules can reduce the maintenance down time and decrease the cost of ownership (COO).

Abstract: An optical metrology model is created for a structure formed on a semiconductor wafer. The optical metrology model comprises one or more profile parameters, one or more process parameters, and dispersion. A dispersion function is obtained that relates the dispersion to at least one of the one or more process parameters. A simulated diffraction signal is generated using the optical metrology model and a value for the at least one of the process parameters and a value for the dispersion. The value for the dispersion is calculated using the value for the at least one of the process parameter and the dispersion function. A measured diffraction signal of the structure is obtained. The measured diffraction signal is compared to the simulated diffraction signal. One or more profile parameters of the structure and one or more process parameters are determined based on the comparison of the measured diffraction signal to the simulated diffraction signal.

Abstract: Provided is a method of optimizing sensitivity of measurements of an optical metrology tool using two or more illumination beams directed to a structure on a workpiece comprising selecting target structures for measurement, obtaining diffraction signals off the selected structures as a function of angle of incidence for each illumination beam, determining a selected angle of incidence for each of the two or more illumination beams, setting sensitivity objectives for optical metrology measurements, developing a design for the optical metrology tool to achieve the corresponding selected angle of incidence of the two or more illumination beams, obtaining sensitivity data using the optical metrology tool, and if the sensitivity objectives are not met, adjusting the selection of target structures, the selected angle of incidence of the two or more illumination beams, the sensitivity objectives, and/or the design of the optical metrology tool, and iterating the developing of the design, obtaining sensitivity data,

Abstract: An Integrated Metrology Sensor (IMS) including a plurality of Field Replaceable Units (FRUs) for measuring a target on a wafer. The FRU configurations can be optimized to include the appropriate elements, so that each FRU can be pre-aligned and calibrated in the factory to minimize the time need to swap the FRU in the field due to failure or scheduled maintenance. The FRU configuration of the IMS is optimized to shorten the time to repair a failure or perform scheduled maintenance and increase the system reliability.

Abstract: The invention can provide apparatus and methods for processing wafers using Noise-Reduction (N-R) metrology models that can be used in Double-Patterning (D-P) processing sequences, Double-Exposure (D-E) processing sequences, or other processing sequences.

Abstract: Provided is a method for determining one or more profile parameters of a structure using an optical metrology model, the optical metrology model comprising a profile model, an approximation diffraction model, and a fine diffraction model. A simulated approximation diffraction signal is generated based on an approximation diffraction model of the structure. A set of difference diffraction signals is obtained by subtracting the simulated approximation diffraction signal from each of simulated fine diffraction signals and paired with the corresponding profile parameters and used to generate a library of difference diffraction signals. A measured diffraction signal adjusted by the simulated approximation diffraction signal is matched against the library to determine at least one profile parameter of the structure.

Abstract: Provided is a method of determining one or more profile parameters of a photomask covered with a pellicle, the method comprising developing an optical metrology model of a pellicle covering a photomask, developing an optical metrology model of the photomask, the photomask separated from the pellicle by a medium and having a structure, the structure having profile parameters, the optical metrology model of the photomask taking into account the optical effects on the illumination beam transmitted through the pellicle and diffracted by the photomask structure. The optical metrology model of the pellicle and the optical metrology model of the photomask structure are integrated and optimized. At least one profile parameters of the photomask structure is determined using the optimized integrated optical metrology model.

Abstract: A method for improving computation efficiency for diffraction signals in optical metrology is described. The method includes simulating a set of diffraction orders for a three-dimensional structure. The diffraction orders within the set of diffraction orders are then prioritized. The set of diffraction orders is truncated to provide a truncated set of diffraction orders based on the prioritizing. Finally, a simulated spectrum is provided based on the truncated set of diffraction orders.

Abstract: A Pre-Aligned Metrology System comprising a number of Pre-Aligned Metrology Assemblies and Pre-Aligned Metrology Modules for measuring a target on a wafer. The Pre-Aligned Metrology Assemblies and Pre-Aligned Metrology Modules can reduce the maintenance down time and decrease the cost of ownership (COO).

Abstract: An improved procedure for calibrating the azimuth angle in a metrology module for use in a metrology system that is used for measuring a target on a wafer, and the metrology modules can include oblique Spectroscopic Ellipsometry (SE) and unpolarized or polarized spectroscopic reflectometer devices.

Abstract: An Integrated Metrology Sensor (IMS) including a plurality of Field Replaceable Units (FRUs) for measuring a target on a wafer. The FRU configurations can be optimized to include the appropriate elements, so that each FRU can be pre-aligned and calibrated in the factory to minimize the time need to swap the FRU in the field due to failure or scheduled maintenance. The FRU configuration of the IMS is optimized to shorten the time to repair a failure or perform scheduled maintenance and increase the system reliability.

Abstract: A fabrication cluster can be controlled using optical metrology. A fabrication process is performed on a wafer using a fabrication cluster. A photonic nanojet, an optical intensity pattern induced at a shadow-side surface of a dielectric microsphere, is generated. An inspection area on the wafer is scanned with the photonic nanojet. A measurement is obtained of the retroreflected light from the dielectric microsphere as the photonic nanojet scans the inspection area. The existence of a structure in the inspection area is determined with the obtained measurement of the retroreflected light. One or more process parameters of the fabrication cluster is adjusted based on the determination of the existence of the structure in the inspection area.