Abstract: A system and method for characterizing an imaging system causes a diffraction image indicative of a test structure having a generalized line-grating to be formed and then extracts from a measurement of the diffraction image a lens transmittance function, a photoresist property or a defocus distance.

Abstract: An apparatus and method for modifying a mask data set includes calculating a derivative of a figure-of-merit, indicative of a data set defined by a plurality of polygon edges and then segmenting polygon edges in response to said step of calculating.

Abstract: A method of modifying polygons in a data set mask-less or mask based optical projection lithography includes: 1) mapping the data set to a figure-of-demerit; 2) moving individual polygon edges to decrease the figure-of-demerit; and 3) disrupting the set of polygons to enable a further decrease in the figure-of-demerit, wherein disrupting polygons includes any of the following polygon disruptions: breaking up, merging, or deleting polygons.

Abstract: An apparatus and method of compensating for lens imperfections in a projection lithography tool, includes extracting from a diffraction image created by the projection lithography tool a lens transmittance function, and then using the extracted lens transmittance function as a compensator in the lithography projection tool. Another preferred apparatus and method of synthesizing a photomask pattern includes obtaining a phase and an amplitude of a transmittance function of an imaging system; forming a computational model of patterning that includes the transmittance function of the imaging system; and then synthesizing a mask pattern from a given target pattern, by minimizing differences between the target pattern and another pattern that the computational model predicts the synthesized mask pattern will form on a wafer.

Abstract: An apparatus and method of synthesizing a photolithographic data set includes using a first computational model to calculate a first figure-of-merit for the photolithographic data set; changing a first part of the photolithographic data set to increase the first figure-of-merit; and then using a second computational model to calculate a second figure-of-merit of the photolithographic data set; and changing a second part of the photolithographic data set to increase the second figure-of-merit. The second computational model enables figure-of-merit calculations to be executed at a significantly faster execution rate that the first computational model.

Abstract: An apparatus and method for improving image quality in a photolithographic process includes calculating a figure-of-demerit for a photolithographic mask function and then adjusting said photolithographic mask function to reduce the figure of demerit.

Abstract: A calibration method suitable for highly precise and highly accurate surface metrology measurements is described. In preferred embodiments, an optical inspection tool including a movable optics system is characterized in terms of position and wavelength dependent quantities over a range of motion. Once the position-dependant quantities are determined at various wavelengths and positions, they are stored and used to interpret data from test wafers having an unknown metrology. Free of position-dependent variations and other information pertaining to the measurement system, the accuracy of the resulting wafer measurement more closely matches the precision of the tool than existing techniques. In particular embodiments, a portion of the characterization of the optical system is accomplished by using tilted black glass to provide a non-reflective reference.

Abstract: A phase-sensitive interferometric broadband reflectometer includes an illumination source for generating an optical beam. A beam splitter or other optical element splits the optical beam into probe beam and reference beam portions. The probe beam is reflected by a subject under test and then rejoined with the reference beam. The combination of the two beams creates an interference pattern that may be modulated by changing the length of the path traveled by the probe or reference beams. The combined beam is received and analyzed by a spectrometer.

Abstract: A calibration method suitable for highly precise and highly accurate surface metrology measurements is described. In preferred embodiments, an optical inspection tool including a movable optics system is characterized in terms of position and wavelength dependent quantities over a range of motion. Once the position-dependant quantities are determined at various wavelengths and positions, they are stored and used to interpret data from test wafers having an unknown metrology. Free of position-dependent variations and other information pertaining to the measurement system, the accuracy of the resulting wafer measurement more closely matches the precision of the tool than existing techniques. In particular embodiments, a portion of the characterization of the optical system is accomplished by using tilted black glass to provide a non-reflective reference.

Abstract: A calibration method suitable for highly precise and highly accurate surface metrology measurements is described. In preferred embodiments, an optical inspection tool including a movable optics system is characterized in terms of position and wavelength dependent quantities over a range of motion. Once the position-dependant quantities are determined at various wavelengths and positions, they are stored and used to interpret data from test wafers having an unknown metrology. Free of position-dependent variations and other information pertaining to the measurement system, the accuracy of the resulting wafer measurement more closely matches the precision of the tool than existing techniques. In particular embodiments, a portion of the characterization of the optical system is accomplished by using tilted black glass to provide a non-reflective reference.

Abstract: An optical metrology system is disclosed which is configured to minimize the measurement of specularly reflected light and measure primarily scattered light. The system is similar to prior art beam profile measurements but includes a movable baffle to selectively block specularly reflected light. In addition, certain non-periodic, isolated targets are disclosed suitable for evaluating overlay registration.

Abstract: Alignment accuracy between two or more patterned layers is measured using a metrology target comprising substantially overlapping diffraction gratings formed in a test area of the layers being tested. An optical instrument illuminates all or part of the target area and measures the optical response. The instrument can measure transmission, reflectance, and/or ellipsometric parameters as a function of wavelength, polar angle of incidence, azimuthal angle of incidence, and/or polarization of the illumination and detected light. Overlay error or offset between those layers containing the test gratings is determined by a processor programmed to calculate an optical response for a set of parameters that include overlay error, using a model that accounts for diffraction by the gratings and interaction of the gratings with each others' diffracted field. The model parameters might also take account of manufactured asymmetries.

Abstract: An optical metrology system is disclosed which is configured to minimize the measurement of specularly reflected light and measure primarily scattered light. The system is similar to prior art beam profile measurements but includes an optical arrangement for increasing the amount of scattered light being monitored in comparison to the amount of specularly reflected light being monitored.

Abstract: First and second exposures of a mask onto a wafer are performed such that the exposure field of the second exposure partially overlaps the exposure field of the first exposure. A characteristic of a set of features is determined, and a value of a parameter of an optical proximity correction model is determined. An alignment feature can be used to align a measurement tool. In yet another embodiment, pupil intensity distribution of an imaging system is measured by exposing an image field of a radiation detector with a bright feature, positioning the detector at a distance away from the image plane, and exposing the image field of the detector with a bright feature, resulting in a cumulative exposure of the image field of the detector from the two exposures. A characteristic of a spatial pattern in the cumulative exposure of the image field of the detector is then determined.

Abstract: Pupil intensity distribution of an imaging system is measured by exposing an image field of a radiation detector with a bright feature, positioning the detector at a distance away from the image plane, and exposing the image field of the detector with a bright feature, resulting in a cumulative exposure of the image field of the detector from the two exposures. A characteristic of a spatial pattern in the cumulative exposure of the image field of the detector is then determined.

Abstract: A method and system for reducing the computation time required to apply position-dependent corrections to lithography, usually mask, data is disclosed. Optical proximity or process corrections are determined for a few instances of a repeating cluster or object, usually at widely separated locations and then interpolating the corrections to the other instances of the repeating cluster based on their positions in the exposure field. Or, optical proximity corrections can be applied to the repeating cluster of objects for different values of flare intensity, or another parameter of patterning imperfection, such as by calculating the value of the flare at the location of each instance of the repeating cluster, and interpolating the optical proximity corrections to those values of flare.

Abstract: Flare of an imaging system is measured using resist by employing the imaging system to directly expose a first part of the resist at an image plane of the imaging system to a first dose of radiation and to indirectly expose a second part of the resist as a result of flare. The imaging system exposes the second part of the resist to a second dose of radiation. Flare of the imaging system is determined from a pattern that is formed in the second part of the resist.

Abstract: A phase-sensitive interferometric broadband reflectometer includes an illumination source for generating an optical beam. A beam splitter or other optical element splits the optical beam into probe beam and reference beam portions. The probe beam is reflected by a subject under test and then rejoined with the reference beam. The combination of the two beams creates an interference pattern that may be modulated by changing the length of the path traveled by the probe or reference beams. The combined beam is received and analyzed by a spectrometer.

Abstract: A phase-sensitive interferometeric broadband reflectometer includes an illumination source for generating an optical beam. A beam splitter or other optical element splits the optical beam into probe beam and reference beam portions. The probe beam is reflected by a subject under test and then rejoined with the reference beam. The combination of the two beams creates an interference pattern that may be modulated by changing the length of the path traveled by the probe or reference beams. The combined beam is received and analyzed by a spectrometer.

Abstract: An optical metrology system is disclosed which is configured to minimize the measurement of specularly reflected light and measure primarily scattered light. The system is similar to prior art beam profile measurements but includes a movable baffle to selectively block specularly reflected light. In addition, certain non-periodic, isolated targets are disclosed suitable for evaluating overlay registration.