摘要:
Methods according to the present invention provide computationally efficient techniques for designing gauge patterns for calibrating a model for use in a simulation process, and which minimize degeneracy between model parameters, and thus maximize pattern coverage for parameter calibration. More specifically, the present invention relates to methods of designing gauge patterns that achieve complete coverage of parameter variations with minimum number of gauges and corresponding measurements in the calibration of a lithographic process utilized to image a target design having a plurality of features. According to some aspects, a method according to the invention includes transforming the space of model parametric space (based on CD sensitivity or Delta TCCs), then iteratively identifying the direction that is most orthogonal to existing gauges' CD sensitivities in this new space, and determining most sensitive line width/pitch combination with optimal assist feature placement which leads to most sensitive CD changes along that direction in model parametric space.
摘要:
Methods according to the present invention provide computationally efficient techniques for designing gauge patterns for calibrating a model for use in a simulation process, and which minimize degeneracy between model parameters, and thus maximize pattern coverage for parameter calibration. More specifically, the present invention relates to methods of designing gauge patterns that achieve complete coverage of parameter variations with minimum number of gauges and corresponding measurements in the calibration of a lithographic process utilized to image a target design having a plurality of features. According to some aspects, a method according to the invention includes transforming the space of model parametric space (based on CD sensitivity or Delta TCCs), then iteratively identifying the direction that is most orthogonal to existing gauges' CD sensitivities in this new space, and determining most sensitive line width/pitch combination with optimal assist feature placement which leads to most sensitive CD changes along that direction in model parametric space.
摘要:
The present invention generally relates to simulating a lithographic process, and more particularly to methods for smart selection and smart weighting when selecting parameters and/or kernels used in aerial image computation. According to one aspect, advantages in simulation throughput and/or accuracy can be achieved by selecting TCC kernels more intelligently, allowing highly accurate aerial images to be simulated using a relatively fewer number of TCC kernels than in the state of the art. In other words, the present invention allows for aerial images to be simulated with the same or better accuracy using much less simulation throughput than required in the prior art, all else being equal.
摘要:
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. The SRAF guidance map can be used directly to place SRAFs in a mask layout. Mask layout data including SRAFs may be generated, wherein the SRAFs are placed according to the SRAF guidance map. The SRAF guidance map can comprise an image in which each pixel value indicates whether the pixel would contribute positively to edge behavior of features in the mask layout if the pixel is included as part of a sub-resolution assist feature.
摘要:
A method of providing targeted online advertisement includes receiving a request for an ad impression to be provided to a user in a network environment. The request includes a first content and a second content. The method also includes, using a processor, determining a context of the first content and a context of the second content, determining a correlation between the context of the first content and the context of the second content, and identifying a plurality of ads as candidates for consideration. The method further includes, using the processor, ranking the plurality of identified ads, selecting an ad among the plurality of identified ads based at least in part on a result of the ranking, and providing the selected ad as the ad impression to be displayed to the user in response to receiving the request.
摘要:
A method of optimizing an illumination pupil shape for a lithographic process comprises identifying a target pattern to be imaged by said lithographic process. It further comprises identifying at least one optimization point in said target pattern and identifying at least one design for manufacturing metric per optimization point. Additionally, it comprises selecting a set of illumination source points based on the identified at least one design for manufacturing metric and determining the illumination pupil shape based on the selected set of illumination source points.
摘要:
A method of efficient simulating 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 generating the simulated image utilizing the function, where the simulated image represents the imaging result of the target design for the lithographic process.
摘要:
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.
摘要:
Embodiments of the present invention provide methods for optimizing a lithographic projection apparatus including optimizing projection optics therein, and preferably including optimizing a source, a mask, and the projection optics. The projection optics is sometimes broadly referred to as “lens”, and therefore the joint optimization process may be termed source mask lens optimization (SMLO). SMLO is desirable over existing source mask optimization process (SMO), partially because including the projection optics in the optimization can lead to a larger process window by introducing a plurality of adjustable characteristics of the projection optics. The projection optics can be used to shape wavefront in the lithographic projection apparatus, enabling aberration control of the overall imaging process. According to the embodiments herein, the optimization can be accelerated by iteratively using linear fitting algorithm or using Taylor series expansion using partial derivatives of transmission cross coefficients (TCCs).
摘要:
The present invention relates to a method for tuning lithography systems so as to allow different lithography systems to image different patterns utilizing a known process that does not require a trial and error process to be performed to optimize the process and lithography system settings for each individual lithography system. According to some aspects, the present invention relates to a method for a generic model-based matching and tuning which works for any pattern. Thus it eliminates the requirements for CD measurements or gauge selection. According to further aspects, the invention is also versatile in that it can be combined with certain conventional techniques to deliver excellent performance for certain important patterns while achieving universal pattern coverage at the same time.