Abstract: A method of optimizing an illumination pupil shape for a lithographic process 1 comprises identifying a target pattern (206) to be imaged by said lithographic process. It further comprises identifying at least one optimization point (262) in said target pattern and identifying at least one design for manufacturing metric (270) per optimization point. Additionally it comprises selecting a set of illumination source points (274) based on the identified at least one design for manufacturing metric and determining the illumination pupil shape (284) based on the selected set of illumination source points.

Abstract: The method of the invention tracks how the collective movement of edge segments in a mask layout alters the resist image values at control points in the layout and simultaneously determines a correction amount for each edge segment in the layout. A multisolver matrix that represents the collective effect of movements of each edge segment in the mask layout is used to simultaneously determine the correction amount for each edge segment in the mask layout.

Abstract: A three-dimensional mask model of the invention provides a more realistic approximation of the three-dimensional effects of a photolithography mask with sub-wavelength features than a thin-mask model. In one embodiment, the three-dimensional mask model includes a set of filtering kernels in the spatial domain that are configured to be convolved with thin-mask transmission functions to produce a near-field image. In another embodiment, the three-dimensional mask model includes a set of correction factors in the frequency domain that are configured to be multiplied by the Fourier transform of thin-mask transmission functions to produce a near-field image.

Abstract: A method for identifying process window signature patterns in a device area of a mask is disclosed. The signature patterns collectively provide a unique response to changes in a set of process condition parameters to the lithography process. The signature patterns enable monitoring of associated process condition parameters for signs of process drift, analyzing of the process condition parameters to determine which are limiting and affecting the chip yields, analyzing the changes in the process condition parameters to determine the corrections that should be fed back into the lithography process or forwarded to an etch process, identifying specific masks that do not transfer the intended pattern to wafers as intended, and identifying groups of masks that share common characteristics and behave in a similar manner with respect to changes in process condition parameters when transferring the pattern to the wafer.

Abstract: One embodiment of a method for process window optimized optical proximity correction includes applying optical proximity corrections to a design layout, simulating a lithography process using the post-OPC layout and models of the lithography process at a plurality of process conditions to produce a plurality of simulated resist images. A weighted average error in the critical dimension or other contour metric for each edge segment of each feature in the design layout is determined, wherein the weighted average error is an offset between the contour metric at each process condition and the contour metric at nominal condition averaged over the plurality of process conditions. A retarget value for the contour metric for each edge segment is determined using the weighted average error and applied to the design layout prior to applying further optical proximity corrections.

Abstract: Methods are disclosed for selecting and optimizing an exposure tool using an individual mask error model. In one embodiment, a method includes selecting a model of a lithography process including an optical model of an exposure tool and a resist model, creating an individual mask error model representing a mask manufactured using mask layout data, simulating the lithography process using the model of the lithography process and the individual mask error model to produce simulated patterns, determining differences between the simulated patterns and a design target, and optimizing settings of the exposure tool based on the differences between the simulated patterns and the design target.

Abstract: Methods and systems are disclosed to inspect a manufactured lithographic mask, to extract physical mask data from mask inspection data, to determine systematic mask error data based on differences between the physical mask data and mask layout data, to generate systematic mask error parameters based on the systematic mask error data, to create an individual mask error model with systematic mask error parameters, to predict patterning performance of the lithographic process using a particular mask and/or a particular projection system, and to predict process corrections that optimize patterning performance and thus the final device yield.

Abstract: While a high-resolution 2-dimensional image reconstruction is expected to give the maximum possible amount of information on the aerial image in a projection system, relevant information regarding image quality can be derived from a statistical evaluation of image values. Relevant statistical image data can be derived by sampling at a multitude of non-adjacent locations across a large area, rather than by scanning over many adjacent locations on a small area. Examples of the benefits of the present invention include: (1) it generally does not rely on very precise, repeatable fine alignment of the image sensor array with respect to the mask and/or the projected image; (2) a large number of individual sensor elements are utilized, and image data is generated from a large set of signal values; and (3) it can generate relevant data to assess aerial image quality in a very short data acquisition time.

Abstract: There are many inventions described and illustrated herein. In one aspect, the present invention is directed to a technique of, and system for inspecting integrated circuits, including, for example, patterns projected, provided or formed on a wafer using photomasks, or patterns on the photomask itself. The inspection system and technique of this aspect includes first identifying, determining and/or detecting areas and/or patterns that are potentially defective by removing, filtering and/or eliminating from a set of potential defects any and/or all typical, regular or normal patterns. The identification, determination and/or detection of potential defects may be performed relatively quickly by a rapidly executing algorithm. In this way, a first or “coarse” analysis is performed rapidly and some, many, all or substantially all of the regular, normal or typical patterns are eliminated from further analysis. Thereafter, a second more detailed analysis is performed.

Abstract: A method for separately calibrating an optical model and a resist model of lithography process using information derived from in-situ aerial image measurements to improve the calibration of both the optical model and the resist model components of the lithography simulation model. Aerial images produced by an exposure tool are measured using an image sensor array loaded into the exposure tool. Multiple embodiments of measuring aerial image information and using the measured aerial image information to calibrate the optical model and the resist model are disclosed. The method of the invention creates more accurate and separable optical and resist models, leading to better predictability of the pattern transfer process from mask to wafer, more accurate verification of circuit patterns and how they will actually print in production, and more accurate model-based process control in the wafer fabrication facility.

Abstract: The method of the invention tracks how the collective movement of edge segments in a mask layout alters the resist image values at control points in the layout and simultaneously determines a correction amount for each edge segment in the layout. A multisolver matrix that represents the collective effect of movements of each edge segment in the mask layout is used to simultaneously determine the correction amount for each edge segment in the mask layout.

Abstract: Methods are disclosed to create efficient model-based Sub-Resolution Assist Features (MB-SRAF). An SRAF guidance map is created, where each design target edge location votes for a given field point on whether a single-pixel SRAF placed on this field point would improve or degrade the aerial image over the process window. In one embodiment, the SRAF guidance map is used to determine SRAF placement rules and/or to fine tune already-placed SRAFs. In another embodiment the SRAF guidance map is used directly to place SRAFs in a mask layout.

Abstract: In one aspect, the present invention is a sensor unit for sensing process parameters of a process to manufacture an integrated circuit using integrated circuit processing equipment. In one embodiment, the sensor unit includes a substrate having a wafer-shaped profile and a first sensor, disposed on or in the substrate, to sample a first process parameter. The sensor unit of this embodiment also includes a second sensor, disposed on or in the substrate, to sample a second process parameter wherein the second process parameter is different from the first process parameter. In one embodiment, the sensor unit includes a first source, disposed on or in the substrate, wherein first source generates an interrogation signal and wherein the first sensor uses the interrogation signal from the first source to sample the first process parameter.

Abstract: Methods and systems are disclosed to inspect a manufactured lithographic mask, to extract physical mask data from mask inspection data, to determine systematic mask error data based on differences between the physical mask data and mask layout data, to generate systematic mask error parameters based on the systematic mask error data, to create an individual mask error model with systematic mask error parameters, to predict patterning performance of the lithographic process using a particular mask and/or a particular projection system, and to predict process corrections that optimize patterning performance and thus the final device yield.

Abstract: Methods are disclosed for selecting and optimizing an exposure tool using an individual mask error model. In one embodiment, a method includes selecting a model of a lithography process including an optical model of an exposure tool and a resist model, creating an individual mask error model representing a mask manufactured using mask layout data, simulating the lithography process using the model of the lithography process and the individual mask error model to produce simulated patterns, determining differences between the simulated patterns and a design target, and optimizing settings of the exposure tool based on the differences between the simulated patterns and the design target.

Abstract: A method for identifying process window signature patterns in a device area of a mask is disclosed. The signature patterns collectively provide a unique response to changes in a set of process condition parameters to the lithography process. The signature patterns enable monitoring of associated process condition parameters for signs of process drift, analyzing of the process condition parameters to determine which are limiting and affecting the chip yields, analyzing the changes in the process condition parameters to determine the corrections that should be fed back into the lithography process or forwarded to an etch process, identifying specific masks that do not transfer the intended pattern to wafers as intended, and identifying groups of masks that share common characteristics and behave in a similar manner with respect to changes in process condition parameters when transferring the pattern to the wafer.

Abstract: A method of using an in-situ aerial image sensor array is disclosed to separate and remove the focal plane variations caused by the image sensor array non-flatness and/or by the exposure tool by collecting sensor image data at various nominal focal planes and by determining best focus at each sampling location by analysis of the through-focus data. In various embodiments, the method provides accurate image data at best focus anywhere in the exposure field, image data covering an exposure-dose based process window area, and a map of effective focal plane distortions. The focus map can be separated into contributions from the exposure tool and contributions due to topography of the image sensor array by suitable calibration or self-calibration procedures. The basic method enables a wide range of applications, including for example qualification testing, process monitoring, and process control by deriving optimum process corrections from analysis of the image sensor data.

Abstract: A method for separately calibrating an optical model and a resist model of lithography process using information derived from in-situ aerial image measurements to improve the calibration of both the optical model and the resist model components of the lithography simulation model. Aerial images produced by an exposure tool are measured using an image sensor array loaded into the exposure tool. Multiple embodiments of measuring aerial image information and using the measured aerial image information to calibrate the optical model and the resist model are disclosed. The method of the invention creates more accurate and separable optical and resist models, leading to better predictability of the pattern transfer process from mask to wafer, more accurate verification of circuit patterns and how they will actually print in production, and more accurate model-based process control in the wafer fabrication facility.

Abstract: A system and a method for creating a focus-exposure model of a lithography process are disclosed. The system and the method utilize calibration data along multiple dimensions of parameter variations, in particular within an exposure-defocus process window space. The system and the method provide a unified set of model parameter values that result in better accuracy and robustness of simulations at nominal process conditions, as well as the ability to predict lithographic performance at any point continuously throughout a complete process window area without a need for recalibration at different settings. With a smaller number of measurements required than the prior-art multiple-model calibration, the focus-exposure model provides more predictive and more robust model parameter values that can be used at any location in the process window.

Abstract: There are many inventions described and illustrated herein. In one aspect, the present invention is directed to a technique of, and system for autonomously monitoring fabrication equipment, for example, integrated circuit fabrication equipment. In one embodiment of this aspect of the invention, the present invention is an autonomous monitoring device including one or more event sensors (for example, acceleration, motion, velocity and/or inertial sensing device(s)) to detect a predetermined event of or by the fabrication equipment (for example, an event that is indicative of the onset, commencement, initiation and/or launch of fabrication process or sub-processes of or by the fabrication equipment). In response thereto, one or more process parameter sensors sample, sense, detect, characterize, analyze and/or inspect one or more parameters of the process in real time (i.e., during the fabrication process).