Abstract: A structure formed on a wafer can be examined by directing an incident pulse at the structure, the incident pulse being a sub-picosecond optical pulse. A diffraction pulse resulting from the incident pulse diffracting from the structure is measured. A characteristic of the profile of the structure is then determined based on the measured diffraction pulse.

Abstract: A resolution enhanced optical metrology system to examine a structure formed on a semiconductor wafer includes a source configured to direct an incident beam at the structure through a coupling element. The coupling element is disposed between the source and the structure with a gap having a gap height defined between the coupling element and the structure.

Abstract: An optical metrology system includes a photometric device with a source configured to generate and direct light onto a structure, and a detector configured to detect light diffracted from the structure and to convert the detected light into a measured diffraction signal. A processing module of the optical metrology system is configured to receive the measured diffraction signal from the detector to analyze the structure. The optical metrology system also includes a generic interface disposed between the photometric device and the processing module. The generic interface is configured to provide the measured diffraction signal to the processing module using a standard set of signal parameters. The standard set of signal parameters includes a reflectance parameter chat characterizes the change in intensity of light when reflected on the structure and a polarization parameter that characterizes the change in polarization states of light when reflected on the structure.

Abstract: A weighting function is obtained to enhance measured diffraction signals used in optical metrology. To obtain the weighting function, a measured diffraction signal is obtained. The measured diffraction signal was measured from a site on a wafer using a photometric device. A first weighting function is defined based on noise that exists in the measured diffraction signal. A second weighting function is defined based on accuracy of the measured diffraction signal. A third weighting function is defined based on sensitivity of the measured diffraction signal. A fourth weighting function is defined based on one or more of the first, second, and third weighting functions.

Abstract: Specific wavelengths to use in optical metrology of an integrated circuit can be selected using one or more selection criteria and termination criteria. Wavelengths are selected using the selection criteria, and the selection of wavelengths is iterated until the termination criteria are met.

Abstract: Metrology data from a semiconductor treatment system is transformed using multivariate analysis. In particular, a set of metrology data measured or simulated for one or more substrates treated using the treatment system is obtained. One or more essential variables for the obtained set of metrology data is determined using multivariate analysis. A first metrology data measured or simulated for one or more substrates treated using the treatment system is obtained. The first obtained metrology data is not one of the metrology data in the set of metrology data earlier obtained. The first metrology data is transformed into a second metrology data using the one or more of the determined essential variables.

Abstract: The optimization of an optical metrology model for use in measuring a wafer structure is evaluated. An optical metrology model having metrology model variables, which includes profile model parameters of a profile model, is developed. One or more goals for metrology model optimization are selected. One or more profile model parameters to be used in evaluating the one or more selected goals are selected. One or more metrology model variables to be set to fixed values are selected. One or more selected metrology model variables are set to fixed values. One or more termination criteria for the one or more selected goals are set. The optical metrology model is optimized using the fixed values for the one or more selected metrology model variables. Measurements for the one or more selected profile model parameters are obtained using the optimized optical metrology model. A determination is then made as to whether the one or more termination criteria are met by the obtained measurements.

Abstract: A structure formed on a semiconductor wafer is examined by directing an incident beam at the structure at an incidence angle and a azimuth angle. The incident beam is scanned over a range of azimuth angles to obtain an azimuthal scan. The cross polarization components of diffracted beams are measured during the azimuthal scan.

Abstract: Specific wavelengths to use in optical metrology of an integrated circuit can be selected using one or more selection criteria and termination criteria. Wavelengths are selected using the selection criteria, and the selection of wavelengths is iterated until the termination criteria are met.

Abstract: The optimization of an optical metrology model for use in measuring a wafer structure is evaluated. An optical metrology model having metrology model variables, which includes profile model parameters of a profile model, is developed. One or more goals for metrology model optimization are selected. One or more profile model parameters to be used in evaluating the one or more selected goals are selected. One or more metrology model variables to be set to fixed values are selected. One or more selected metrology model variables are set to fixed values. One or more termination criteria for the one or more selected goals are set. The optical metrology model is optimized using the fixed values for the one or more selected metrology model variables. Measurements for the one or more selected profile model parameters are obtained using the optimized optical metrology model. A determination is then made as to whether the one or more termination criteria are met by the obtained measurements.

Abstract: The profile of a structure having a region with a spatially varying property is modeled using an optical metrology model. A set of profile parameters is defined for the optical metrology model to characterize the profile of the structure. A set of layers is defined for a portion the optical metrology model that corresponds to the region of the structure with the spatially varying property, each layer having a defined height and width. For each layer, a mathematic function that varies across at least a portion of the width of the layer is defined to characterize the spatially varying property within a corresponding layer in the region of the structure.

Abstract: An optical metrology model for a repetitive structure is optimized by selecting one or more profile parameters using one or more selection criteria. One or more termination criteria are set, the one or more termination criteria comprising measures of stability of the optical metrology model. The profile shape features of the repetitive structure are characterized using the one or more selected profile parameters. The optical metrology model is optimized using a set of values for the one or more selected profile parameters. One or more profile parameters of the profile of the repetitive structure are determined using the optimized optical metrology model and one or more measured diffraction signals. Values of the one or more termination criteria are calculated using the one or more determined profile parameters.

Abstract: An exemplary method and system for generating integrated circuit (IC) simulation information regarding the effect of design and fabrication process decisionn includes creating and using a data store of profile-based information comprising metrology signal, structure profile data, process control parameters, and IC simulation attributes. An exemplary method and system for generating a simulation data store using signals off test gratings that model the effect of an IC design and/or fabrication process includes creating and using a simulation data store generated using test gratings that model the geometries of the IC interconnects. The interconnect simulation data store may be used in-line for monitoring electrical and thermal properties of an IC device during fabrication. Other embodiments include utilizing a metrology simulator and various combinations of a fabrication process simulator, a device simulator, and/or circuit simulator.

Abstract: The profile of an integrated circuit structure is determined by obtaining a measured metrology signal and a first simulated metrology signal, which has an associated profile model of the structure defined by a set of profile parameters. When the two signals match within a first termination criterion, at least one profile parameter is selected from the set of profile parameters. A value for the selected profile parameter is determined. A second simulated metrology signal having an associated profile model of the structure defined by a set of profile parameters with at least one profile parameter equal or close to the determined value for the selected profile parameter is obtained. When the measured and the second simulated metrology signals match within a second termination criterion, values for one or more remaining profile parameters are determined from the set of profile parameters associated with the second simulated metrology signal.

Abstract: Split machine learning systems can be used to generate an output for an input. When the input is received, a determination is made as to whether the input is within a first, second, or third range of values. If the input is within the first range, the output is generated using a first machine learning system. If the input is within the second range, the output is generated using a second machine learning system. If the input is within the third range, the output is generated using the first and second machine learning systems.

Abstract: The profile of a single feature formed on a wafer can be determined by obtaining an optical signature of the single feature using a beam of light focused on the single feature. The obtained optical signature can then be compared to a set of simulated optical signatures, where each simulated optical signature corresponds to a hypothetical profile of the single feature and is modeled based on the hypothetical profile.

Abstract: To select a unit cell configuration for a repeating structure in optical metrology, a plurality of unit cell configurations are defined for the repeating structure. Each unit cell configuration is defined by one or more unit cell parameters. Each unit cell of the plurality of unity cell configurations differs from one another in at least one unit cell parameter. One or more selection criteria are used to select one of the plurality of unit cell configurations. The selected unit cell configuration can then be used to characterize the top-view profile of the repeating structure.

Abstract: A structure formed on a wafer can be examined by directing an incident pulse at the structure, the incident pulse being a sub-picosecond optical pulse. A diffraction pulse resulting from the incident pulse diffracting from the structure is measured. A characteristic of the profile of the structure is then determined based on the measured diffraction pulse.

Abstract: A profile model for use in optical metrology of structures in a wafer is selected based on a template having one or more parameters including characteristics of process and modeling attributes associated with a structure in a wafer. The process includes performing a profile modeling process to generate a profile model of a wafer structure based on a template having one or more parameters including characteristics of process and modeling attributes. The profile model includes a set of geometric parameters associated with the dimensions of the structure. The generated profile model may further be tested against termination criteria and the one or more parameters modified. The process of performing a modeling process to generate a profile model and testing the generated profile model may be repeated until the termination criteria are met.

Abstract: A wafer structure profile is modeled by determining one or more termination criteria. A determination is made as to whether a wafer structure includes at least one layer having three or more materials alone a line within the at least one layer. An optical metrology model for the wafer structure is created, where three or more materials are incorporated in the model for the at least one layer having three or more materials. A set of diffraction signals is simulated using the optical metrology model. The set of simulated diffraction signals and a set of diffraction signals measured off of the wafer structure are used to determine if the one or more termination criteria are met. The optical metrology model is modified until the one or more termination criteria are met.