Abstract: A method of calculating process corrections for a lithographic tool, and associated apparatuses. The method comprises measuring process defect data on a substrate that has been previously exposed using the lithographic tool; fitting a process signature model to the measured process defect data, so as to obtain a model of the process signature for the lithographic tool; and using the process signature model to calculate the process corrections for the lithographic tool.

Abstract: A pattern from a patterning device is applied to a substrate by a lithographic apparatus. The applied pattern includes product features and metrology targets. The metrology targets include large targets and small targets which are for measuring overlay. Some of the smaller targets are distributed at locations between the larger targets, while other small targets are placed at the same locations as a large target. By comparing values measured using a small target and large target at the same location, parameter values measured using all the small targets can be corrected for better accuracy. The large targets can be located primarily within scribe lanes while the small targets are distributed within product areas.

Abstract: 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 formed 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.

Abstract: A pattern from a patterning device is applied to a substrate by a lithographic apparatus. The applied pattern includes product features and metrology targets. The metrology targets include large targets and small targets which are for measuring overlay. Some of the smaller targets are distributed at locations between the larger targets, while other small targets are placed at the same locations as a large target. By comparing values measured using a small target and large target at the same location, parameter values measured using all the small targets can be corrected for better accuracy. The large targets can be located primarily within scribe lanes while the small targets are distributed within product areas.

Abstract: A method of calculating process corrections for a lithographic tool, and associated apparatuses. The method comprises measuring process defect data on a substrate that has been previously exposed using the lithographic tool; fitting a process signature model to the measured process defect data, so as to obtain a model of the process signature for the lithographic tool; and using the process signature model to calculate the process corrections for the lithographic tool.

Abstract: A substrate is loaded onto a substrate support of a lithographic apparatus, after which the apparatus measures locations of substrate alignment marks. These measurements define first correction information allowing the apparatus to apply a pattern at one or more desired locations on the substrate. Additional second correction information is used to enhance accuracy of pattern positioning, in particular to correct higher order distortions of a nominal alignment grid. The second correction information may be based on measurements of locations of alignment marks made when applying a previous pattern to the same substrate. The second correction information may alternatively or in addition be based on measurements made on similar substrates that have been patterned prior to the current substrate.

Abstract: A pattern from a patterning device is applied to a substrate by a lithographic apparatus. The applied pattern includes product features and metrology targets. The metrology targets include large targets and small targets which are for measuring overlay. Some of the smaller targets are distributed at locations between the larger targets, while other small targets are placed at the same locations as a large target. By comparing values measured using a small target and large target at the same location, parameter values measured using all the small targets can be corrected for better accuracy. The large targets can be located primarily within scribe lanes while the small targets are distributed within product areas.

Abstract: A target structure including a periodic structure is formed on a substrate. An image of the target structure is detected while illuminating the target structure with a beam of radiation, the image being formed using a first part of non-zero order diffracted radiation while excluding zero order diffracted radiation. Intensity values extracted from a region of interest within the image are used to determine a property of the periodic structure. A processing unit recognizes locations of a plurality of boundary features in the image of the target structure to identify regions of interest. The number of boundary features in each direction is at least twice a number of boundaries of periodic structures within the target structure. The accuracy of locating the region is greater than by recognizing only the boundaries of the periodic structure(s).

Abstract: Methods are disclosed for measuring target structures formed by a lithographic process on a substrate. A grating structure within the target is smaller than an illumination spot and field of view of a measurement optical system. The optical system has a first branch leading to a pupil plane imaging sensor and a second branch leading to a substrate plane imaging sensor. A spatial light modulator is arranged in an intermediate pupil plane of the second branch of the optical system. The SLM imparts a programmable pattern of attenuation that may be used to correct for asymmetries between the first and second modes of illumination or imaging. By use of specific target designs and machine-learning processes, the attenuation patterns may also be programmed to act as filter functions, enhancing sensitivity to specific parameters of interest, such as focus.

Abstract: A method of determining an overlay error. Measuring an overlay target having process-induced asymmetry. Constructing a model of the target. Modifying the model, e.g., by moving one of the structures to compensate for the asymmetry. Calculating an asymmetry-induced overlay error using the modified model. Determining an overlay error in a production target by subtracting the asymmetry-induced overlay error from a measured overlay error. In one example, the model is modified by varying asymmetry p(n?), p(n?) and the calculating an asymmetry-induced overlay error is repeated for a plurality of scatterometer measurement recipes and the step of determining an overlay error in a production target uses the calculated asymmetry-induced overlay errors to select an optimum scatterometer measurement recipe used to measure the production target.

Abstract: 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.

Abstract: A method of manufacturing integrated circuits includes determining a process-induced displacement (e.g., a stress-induced displacement) between primary structures on a substrate and providing a photomask with mask features assigned to the primary structures. The distances between the mask features are set such that the process-induced displacement is compensated.

Abstract: A simulation is carried out of a projection based on an electronically stored circuit pattern and adjustable projection parameters and optical parameters which characterize the specific characteristics of a projection apparatus. Positions at which it is predicted that side lobes will occur in the event of an actual projection are identified in the calculated circuit pattern. The positions of the side lobes are transmitted to a manufacturing unit and are recorded in a measurement program. A wafer, which has been exposed by a mask, is inspected for side lobes, at least at precisely those transmitted positions using the measurement program. The adjustable projection parameters are adapted, a radiation-sensitive layer is removed from and reapplied to the wafer and the projection is repeated with the adapted projection parameters depending on the detection result. The control process is repeated until the side lobes have been completely prevented.

Abstract: A simulation is carried out of a projection based on an electronically stored circuit pattern and adjustable projection parameters and optical parameters which characterize the specific characteristics of a projection apparatus. Positions at which it is predicted that side lobes will occur in the event of an actual projection are identified in the calculated circuit pattern. The positions of the side lobes are transmitted to a manufacturing unit and are recorded in a measurement program. A wafer, which has been exposed by a mask, is inspected for side lobes, at least at precisely those transmitted positions using the measurement program. The adjustable projection parameters are adapted, a radiation-sensitive layer is removed from and reapplied to the wafer and the projection is repeated with the adapted projection parameters depending on the detection result. The control process is repeated until the side lobes have been completely prevented.

Abstract: A method is disclosed enabling a technologically controllable and economical production of a hard-magnetic powder composed of a samarium-cobalt base alloy for highly coercive permanent magnets. The method is based on a HDDR treatment in which a starting powder is subjected to hydrogenation with disproportionation of the alloy in a first method step under hydrogen and, in a subsequent, second method step under vacuum conditions, a hydrogen desorption with recombination of the alloy. A starting powder containing samarium and cobalt is treated in the first method step either at a high temperature in the range of 500° C. to 900° C. and with a high hydrogen pressure of >0.5 MPa or by applying an intensive fine grinding at a low temperature in the range of 50° C. to 500° C. and with a hydrogen pressure of >0.15 MPa.