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.