Patent application number | Description | Published |
20110010000 | Method for Selecting Sample Positions on a Substrate, Method for Providing a Representation of a Model of Properties of a Substrate, Method of Providing a Representation of the Variation of Properties of a Substrate Across the Substrate and Device Manufacturing Method - A method for selecting sample positions on a substrate from a set of all available sample positions is provided, in which a representation of a model, which may represent the variation of one or more properties across the substrate, is analyzed in order to identify the sample positions having the greatest effect on the model. | 01-13-2011 |
20110134419 | Inspection Method and Apparatus, and Corresponding Lithographic Apparatus - A method and associated apparatus determine an overlay error on a substrate. A beam is projected onto three or more targets. Each target includes first and second overlapping patterns with predetermined overlay offsets on the substrate. The asymmetry of the radiation reflected from each target on the substrate is measured. The overlay error not resultant from the predetermined overlay offsets is determined. The function that enables calculation of overlay from asymmetry for other points on the wafer is determined by limiting the effect of linearity error when determining the overlay error from the function. | 06-09-2011 |
20110196646 | Alignment System, Lithographic System and Method - A lithographic system includes a lithographic apparatus comprising a projection system which projects a patterned radiation beam onto a target portion of a substrate and an alignment system which measures the position of a feature of the pattern on the substrate at a number of locations over the substrate. A controller compares the measured positions with points on a grid of values and extrapolates values for intermediate positions on the substrate based on values of corresponding intermediate points on the grid, so as to provide an indication of the intermediate positions on the substrate and their displacements relative to the grid. The grid is based on at least one orthogonal basis function, the measurement on the substrate being performed at positions corresponding to the root values of the at least one orthogonal basis function. | 08-11-2011 |
20110199596 | Method and Apparatus for Estimating Model Parameters of and Controlling a Lithographic Apparatus - System and methods estimate model parameters of a lithographic apparatus and control lithographic processing by a lithographic apparatus. An exposure is performed using a lithographic apparatus across a wafer. A set of predetermined wafer measurement locations is obtained. Discrete orthonormal polynomials are generated using the predetermined substrate measurement locations. The overlay errors arising from the exposure are measured at the predetermined locations to obtain overlay measurements. The estimated model parameters of the lithographic apparatus are calculated from the overlay measurements by using the discrete orthogonal polynomials as a basis function to model the overlay across the wafer. Finally, the estimated model parameters are used to control the lithographic apparatus in order to provide corrected overlay across the wafer. | 08-18-2011 |
20110205511 | Lithographic Apparatus and Device Manufacturing Method - A method controls scanning function of a lithographic apparatus. A monitor wafer is exposed to determine baseline control parameters pertaining to the scanning function. The baseline control parameters are retrieved from the monitor wafer. Parameter drift is determined from the baseline control parameters. Compensation is performed based on the determination. A different parameterization is used for control of the scanning control module than for communication between the scanning control module and the lithographic apparatus. | 08-25-2011 |
20110299050 | Lithographic System, Lithographic Method And Device Manufacturing Method - A lithographic system includes a lithographic apparatus and a scatterometer. In an embodiment, the lithographic apparatus includes an illumination optical system arranged to illuminate a pattern and a projection optical system arranged to project an image of the pattern on to a substrate. In an embodiment, the scatterometer includes a measurement system arranged to direct a beam of radiation onto a target pattern on said substrate and to obtain an image of a pupil plane representative of radiation scattered from the target pattern. A computational arrangement represents the pupil plane by moment functions calculated from a pair of orthogonal basis function and correlates the moment function to lithographic feature parameters to build a lithographic system identification. A control arrangement uses the system identification to control subsequent lithographic processes performed by the lithographic apparatus. | 12-08-2011 |
20130135600 | Inspection Method and Apparatus, and Corresponding Lithographic Apparatus - An inspection method, and corresponding apparatus, enables classification of pupil images according to a process variable. The method comprises acquiring diffraction pupil images of a plurality of structures formed on a substrate during a lithographic process. A process variable of the lithographic process varies between formation of the structures, the variation of the process variable resulting in a variation in the diffraction pupil images. The method further comprises determining at least one discriminant function for the diffraction pupil images, the discriminant function being able to classify the pupil images in terms of the process variable. | 05-30-2013 |
20140176955 | Inspection Methods, Inspection Apparatuses, and Lithographic Apparatuses - A method for determining overlay error includes measuring asymmetry of radiation reflected from each of a plurality of targets on a substrate. The plurality of targets include a predetermined overlay offset. The method also includes comparing the measured asymmetry of the radiation reflected from each of the plurality of targets to the corresponding predetermined overlay offset of the respective target. Additionally, the method includes determining the overlay error of a point on the substrate as a function of measured asymmetry reflected from the point. The function is determined by fitting a polynomial or a Fourier series to a comparison of the measured asymmetry of the radiation reflected from each of the plurality of targets to the corresponding predetermined overlay offset of the respective target. The function limits an effect of linearity error. | 06-26-2014 |