摘要:
Described herein are methods for matching the characteristics of a lithographic projection apparatus to a reference lithographic projection apparatus, where the matching includes optimizing projection optics characteristics. The projection optics can be used to shape wavefront in the lithographic projection apparatus. According to the embodiments herein, the methods can be accelerated by using linear fitting algorithm or using Taylor series expansion using partial derivatives of transmission cross coefficients (TCCs).
摘要:
Methods for calibrating a photolithographic system are disclosed. A cold lens contour for a reticle design and at least one hot lens contour for the reticle design are generated from which a process window is defined. Aberrations induced by a lens manipulator are characterized in a manipulator model and the process window is optimized using the manipulator model. Aberrations are characterized by identifying variations in critical dimensions caused by lens manipulation for a plurality of manipulator settings and by modeling behavior of the manipulator as a relationship between manipulator settings and aberrations. The process window may be optimized by minimizing a cost function for a set of critical locations.
摘要:
Described herein are methods for matching the characteristics of a lithographic projection apparatus to a reference lithographic projection apparatus, where the matching includes optimizing projection optics characteristics. The projection optics can be used to shape wavefront in the lithographic projection apparatus. According to the embodiments herein, the methods can be accelerated by using linear fitting algorithm or using Taylor series expansion using partial derivatives of transmission cross coefficients (TCCs).
摘要:
The various embodiments described in the present disclosure, in at least one aspect, relate to computer-implemented methods of online advertisement. In one embodiment, a method includes, in response to receiving a request for an ad to be provided to a user in an online session, identifying a plurality of ads as candidates for consideration, determining one or more sentiments of a content of the online session, and ranking the plurality of identified ads based at least in part on (i) a correlation between the content of the online session and a content of each identified ad, and (ii) a correlation between the one or more sentiments of the content of the online session and the content of each identified ad.
摘要:
The present invention relates to methods and systems for designing gauge patterns that are extremely sensitive to parameter variation, and thus robust against random and repetitive measurement errors in calibration of a lithographic process utilized to image a target design having a plurality of features. The method may include identifying most sensitive line width/pitch combination with optimal assist feature placement which leads to most sensitive CD (or other lithography response parameter) changes against lithography process parameter variations, such as wavefront aberration parameter variation. The method may also include designing gauges which have more than one test patterns, such that a combined response of the gauge can be tailored to generate a certain response to wavefront-related or other lithographic process parameters. The sensitivity against parameter variation leads to robust performance against random measurement error and/or any other measurement error.
摘要:
A model-based tuning method for tuning a first mask writer unit utilizing a reference mask writer unit, each of which has tunable parameters for controlling mask writing performance. The method includes the steps of defining a test pattern and a mask writing model; generating the test pattern utilizing the reference mask writer unit and measuring the mask writing results; generating the test pattern utilizing the first mask writer unit and measuring the mask writing results; calibrating the mask writing model utilizing the mask writing results corresponding to the reference mask writer unit, where the calibrated mask writing model has a first set of parameter values; tuning the calibrated mask writing model utilizing the mask writing results corresponding to the first mask writer unit, where the tuned calibrated model has a second set of parameter values; and adjusting the parameters of the first mask writer unit based on a difference between the first set of parameter values and the second set of parameter values.
摘要:
A model-based tuning method for tuning a first lithography system utilizing a reference lithography system, each of which has tunable parameters for controlling imaging performance. The method includes the steps of defining a test pattern and an imaging model; imaging the test pattern utilizing the reference lithography system and measuring the imaging results; imaging the test pattern utilizing the first lithography system and measuring the imaging results; calibrating the imaging model utilizing the imaging results corresponding to the reference lithography system, where the calibrated imaging model has a first set of parameter values; tuning the calibrated imaging model utilizing the imaging results corresponding to the first lithography system, where the tuned calibrated model has a second set of parameter values; and adjusting the parameters of the first lithography system based on a difference between the first set of parameter values and the second set of parameter values.
摘要:
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.
摘要:
The present invention relates to an efficient OPC method of increasing imaging performance of a lithographic process utilized to image a target design having a plurality of features. The method includes the steps of determining a function for generating a simulated image, where the function accounts for process variations associated with the lithographic process; and optimizing target gray level for each evaluation point in each OPC iteration based on this function. In one given embodiment, the function is approximated as a polynomial function of focus and exposure, R(ε, f)=P0+f2·Pb with a threshold of T+Vε for contours, where P0 represents image intensity at nominal focus, f represents the defocus value relative to the nominal focus, ε represents the exposure change, V represents the scaling of exposure change, and parameter “Pb” represents second order derivative images. In another given embodiment, the analytical optimal gray level is given for best focus with the assumption that the probability distribution of focus and exposure variation is Gaussian.
摘要:
A model-based tuning method for tuning a first mask writer unit utilizing a reference mask writer unit, each of which has tunable parameters for controlling mask writing performance. The method includes the steps of defining a test pattern and a mask writing model; generating the test pattern utilizing the reference mask writer unit and measuring the mask writing results; generating the test pattern utilizing the first mask writer unit and measuring the mask writing results; calibrating the mask writing model utilizing the mask writing results corresponding to the reference mask writer unit, where the calibrated mask writing model has a first set of parameter values; tuning the calibrated mask writing model utilizing the mask writing results corresponding to the first mask writer unit, where the tuned calibrated model has a second set of parameter values; and adjusting the parameters of the first mask writer unit based on a difference between the first set of parameter values and the second set of parameter values.