Abstract: A method of optimizing an apparatus for multi-stage processing of product units such as wafers, the method includes: receiving object data representing one or more parameters measured across the product units and associated with different stages of processing of the product units; and determining fingerprints of variation of the object data across the product units, the fingerprints being associated with different respective stages of processing of the product units. The fingerprints may be determined by decomposing the object data into components using principal component analysis for each different respective stage; analyzing commonality of the fingerprints through the different stages to produce commonality results; and optimizing an apparatus for processing product units based on the commonality results.

Abstract: A method of optimizing an apparatus for multi-stage processing of product units such as wafers, the method includes: receiving object data representing one or more parameters measured across the product units and associated with different stages of processing of the product units; and determining fingerprints of variation of the object data across the product units, the fingerprints being associated with different respective stages of processing of the product units. The fingerprints may be determined by decomposing the object data into components using principal component analysis for each different respective stage; analyzing commonality of the fingerprints through the different stages to produce commonality results; and optimizing an apparatus for processing product units based on the commonality results.

Abstract: A method of optimizing an apparatus for multi-stage processing of product units such as wafers, the method includes: receiving object data representing one or more parameters measured across the product units and associated with different stages of processing of the product units; and determining fingerprints of variation of the object data across the product units, the fingerprints being associated with different respective stages of processing of the product units. The fingerprints may be determined by decomposing the object data into components using principal component analysis for each different respective stage; analyzing commonality of the fingerprints through the different stages to produce commonality results; and optimizing an apparatus for processing product units based on the commonality results.

Abstract: A method of maintaining a set of fingerprints representing variation of one or more process parameters across wafers subjected to a device manufacturing method, the method including: receiving measurement data of one or more parameters measured on wafers; updating the set of fingerprints based on an expected evolution of the one or more process parameters; and evaluation of the updated set of fingerprints based on decomposition of the received measurement data in terms of the updated set of fingerprints. Each fingerprint may have a stored likelihood of occurrence, and the decomposition may involve: estimating, based the received measurement data, likelihoods of occurrence of the set of fingerprints in the received measurement data; and updating the stored likelihoods of occurrence based on the estimated likelihoods.

Abstract: A method of maintaining a set of fingerprints representing variation of one or more process parameters across wafers subjected to a device manufacturing method, the method including: receiving measurement data of one or more parameters measured on wafers; updating the set of fingerprints based on an expected evolution of the one or more process parameters; and evaluation of the updated set of fingerprints based on decomposition of the received measurement data in terms of the updated set of fingerprints. Each fingerprint may have a stored likelihood of occurrence, and the decomposition may involve: estimating, based the received measurement data, likelihoods of occurrence of the set of fingerprints in the received measurement data; and updating the stored likelihoods of occurrence based on the estimated likelihoods.

Abstract: A method of optimizing an apparatus for multi-stage processing of product units such as wafers, the method includes: receiving object data representing one or more parameters measured across the product units and associated with different stages of processing of the product units; and determining fingerprints of variation of the object data across the product units, the fingerprints being associated with different respective stages of processing of the product units. The fingerprints may be determined by decomposing the object data into components using principal component analysis for each different respective stage; analyzing commonality of the fingerprints through the different stages to produce commonality results; and optimizing an apparatus for processing product units based on the commonality results.

Abstract: The invention relates to a level sensor for use in a lithographic apparatus that determines a surface height of a substrate. The level sensor includes an emitter and a receiver, wherein the emitter is arranged to emit a signal directed to a predetermined position on the surface of the substrate, such that the signal is at least partially reflected by the substrate to render a reflected signal. The receiver is arranged to receive at least part of the reflected signal, and the level sensor is arranged to determine the surface height of the substrate with respect to the level sensor based on the emitted and received signal. The signal includes a pressure wave.

Abstract: According to one embodiment, a method of calibrating level sensors of at least two lithographic projection apparatus to correct machine to machine level sensor process dependency includes using a first lithographic projection apparatus to measure a first set of leveling data for a reference substrate and a second set of leveling data for a substrate processed according to a selected process, and using a second lithographic projection apparatus to measure a third set of leveling data for the reference substrate and a fourth set of leveling data for the processed substrate. The method also includes calculating, based on the first, second, third and fourth sets of leveling data, a set of level sensor parameters corresponding to machine to machine level sensor differences for the selected process, wherein the machine to machine level sensor differences are measured and stored as intrafield values.

Abstract: The invention pertains to a technique for determining the dye uptake or measuring one or more structural parameters or mechanical properties of polymeric fibres. This technique entails measuring the Raman spectrum of the fibres during or after a spinning process. After the Raman spectrum has been treated, a model is applied to it which is derived from the Raman spectra of fibres having the same chemical composition as the fibres to be examined.