| Patent application number | Description | Published |
|---|
| 20080239277 | Method of forming a substrate for use in calibrating a metrology tool, calibration substrate and metrology tool calibration method - The present invention provides a method for forming a substrate for use in calibrating a metrology tool in order to compensate for orientation-dependent variations within the metrology tool. | 10-02-2008 |
| 20080279442 | Inspection method and apparatus, lithographic apparatus, lithographic processing cell and device manufacturing method - A method of measuring a property of a substrate includes generating a patterned mask configured to cause a radiation beam passing through the mask to acquire the pattern, simulating radiating the substrate with a patterned radiation beam that has been patterned using the mask to obtain a simulated pattern, determining at least one location of the simulated pattern that is prone to patterning errors, and irradiating the substrate with the patterned radiation beam using a lithographic process. The method also includes measuring an accuracy of at least one property of the at least one location of the pattern on the substrate that has been determined as being prone to patterning errors, and adjusting the lithographic process according to the measuring. | 11-13-2008 |
| 20090094005 | Method of Optimizing a Model, a Method of Measuring a Property, A Device Manufacturing Method, a Spectrometer and a Lithographic Apparatus - A set of parameters used in a model of a spectrometer includes free parameters and fixed parameters. A first set of values for the parameters is set and the model is used to generate a first spectrum. A value of one of the fixed parameters is changed and a second spectrum is generated. An inverse of the model of the spectrometer is then applied to the second spectrum to generate a set of values for the parameters, the values being the same as the first set of values except for one or more of the free parameters. If the free parameter has significantly changed the fixed parameter is designated a free parameter. | 04-09-2009 |
| 20090135424 | Inspection Method and Apparatus, Lithographic Apparatus, Lithographic Processing Cell and Device Manufacturing Method for Determining A Parameter of a Target Pattern - In a method for determining a structure parameter of a target pattern, a first series of calibration spectra are determined from at least one reference pattern, each spectra being determined using a different known value of at least one structure parameter of the respective reference pattern. The first series of calibration spectra does not take into account parameters of an apparatus used to produce the reference pattern. A representation of each of the first series calibration spectra is stored in a central library. A second series of calibration spectra corresponding to at least one of the stored spectra for a target spectrum is determined using the parameters of the apparatus for measuring the target spectrum. A measured target spectrum is produced by directing a beam of radiation onto the target pattern. The measured target spectrum and the second series of calibration spectra are compared, where this comparison is used to derive a value for the structure parameter of the target pattern. | 05-28-2009 |
| 20100201963 | Inspection Apparatus, Lithographic Apparatus, Lithographic Processing Cell and Inspection Method - For angular resolved spectrometry a radiation beam is used having an illumination profile having four quadrants is used. The first and third quadrants are illuminated whereas the second and fourth quadrants aren't illuminated. The resulting pupil plane is thus also divided into four quadrants with only the zeroth order diffraction pattern appearing in the first and third quadrants and only the first order diffraction pattern appearing in the second and third quadrants. | 08-12-2010 |
| 20110026032 | Method of Assessing a Model of a Substrate, an Inspection Apparatus and a Lithographic Apparatus - A method of assessing a model of a substrate is presented. A scatterometry measurement is taken using radiation at a first wavelength. The wavelength of the radiation is then changed and a further scatterometry measurement taken. If the scatterometry measurements are consistent across a range of wavelengths then the model is sufficiently accurate. However, if the scatterometry measurements change as the wavelength changes then the model of the substrate is not sufficiently accurate. | 02-03-2011 |
| 20110027704 | Methods and Scatterometers, Lithographic Systems, and Lithographic Processing Cells - In a method of determining the focus of a lithographic apparatus used in a lithographic process on a substrate, the lithographic process is used to form a structure on the substrate, the structure having at least one feature which has an asymmetry in the printed profile which varies as a function of the focus of the lithographic apparatus on the substrate. A first image of the periodic structure is formed and detected while illuminating the structure with a first beam of radiation. The first image is formed using a first part of non-zero order diffracted radiation. A second image of the periodic structure is foamed and detected while illuminating the structure with a second beam of radiation. The second image is formed using a second part of the non-zero order diffracted radiation which is symmetrically opposite to the first part in a diffraction spectrum. The ratio of the intensities of the measured first and second portions of the spectra is determined and used to determine the asymmetry in the profile of the periodic structure and/or to provide an indication of the focus on the substrate. In the same instrument, an intensity variation across the detected portion is determined as a measure of process-induced variation across the structure. A region of the structure with unwanted process variation can be identified and excluded from a measurement of the structure. | 02-03-2011 |
| 20110085176 | Method, Inspection Apparatus and Substrate for Determining an Approximate Structure of an Object on a Substrate - A system and method determine an approximate structure of an object on a substrate. This may be applied in model based metrology of microscopic structures to assess critical dimension or overlay performance of a lithographic apparatus. A scatterometer is used to determine approximate structure of an object, such as a grating on a stack, on a substrate. The wafer substrate has an upper layer and an underlying layer. The substrate has a first scatterometry target region, including the grating on a stack object. The grating on a stack is made up of the upper and underlying layers. The upper layer is patterned with a periodic grating. The substrate further has a neighboring second scatterometry target region, where the upper layer is absent. The second region has just the unpatterned underlying layers. | 04-14-2011 |
