Abstract: A method is provided for determining the position of a first structure (8a) relative to a second structure (8b) or a part thereof, said method having the steps of: a) providing a first picture (F1) having a multiplicity of pixels and which contains the first structure, b) providing a second picture (F2) having a multiplicity of pixels and which contains the second structure, c) forming an optimization function with the displacement of the two pictures relative to one another as parameter, the optimization function overlying the two pictures and masking the overlay such that in a determination of an extreme value of the optimization function a contribution is made only by the region of the overlay that corresponds to the second structure or the part thereof, d) ascertaining the extreme value of the optimization function and determining the optimal value of the displacement based on the extreme value of the optimization function, and e) determining the position of the first structure relative to the second stru

Abstract: A method and an apparatus for determining the position of a structure on a mask for microlithography, in which the position is determined by comparing an aerial image, measured by a recording device, of a portion of the mask with an aerial image determined by simulation. The position determination includes carrying out a plurality of such comparisons which differ from one another with regard to the input parameters of the simulation.

Abstract: There is provided an autofocus device for an imaging device which has an imaging lens system with a first focal plane, an object stage for holding an object, and a first movement module for the relative movement of object stage and imaging lens system. The autofocus device comprises an image-recording module with a second focal plane, a second movement module for the relative movement of object stage and image-recording module, and a control module which controls the image-recording module for focusing the imaging device. The control module controls the first movement module such that evaluated change in distance between the object stage and the imaging lens system is carried out, and controls the second movement module such that, during the first exposure time for recording the first two-dimensional image, the object stage is moved relative to the image-recording module in a plane parallel to the second focal plane.

Abstract: A method and an apparatus for determining the position of a structure on a mask for microlithography, in which the position is determined by comparing an aerial image, measured by a recording device, of a portion of the mask with an aerial image determined by simulation. The position determination includes carrying out a plurality of such comparisons which differ from one another with regard to the input parameters of the simulation.

Abstract: A method is provided for determining the position of a first structure (8a) relative to a second structure (8b) or a part thereof, said method having the steps of: a) providing a first picture (F1) having a multiplicity of pixels and which contains the first structure, b) providing a second picture (F2) having a multiplicity of pixels and which contains the second structure, c) forming an optimization function with the displacement of the two pictures relative to one another as parameter, the optimization function overlying the two pictures and masking the overlay such that in a determination of an extreme value of the optimization function a contribution is made only by the region of the overlay that corresponds to the second structure or the part thereof, d) ascertaining the extreme value of the optimization function and determining the optimal value of the displacement based on the extreme value of the optimization function, and e) determining the position of the first structure relative to the second stru

Abstract: A method for determining a registration error of a feature on a mask, including providing a first aerial image that was captured by means of a position measuring device and includes at least the feature, simulating, from pattern specifications of the mask, a second aerial image that includes at least the feature, taking into account at least one effect that causes distortion of the first aerial image, and determining the registration error of the feature as the distance of the position of the feature in the first aerial image from the position of the feature in the second aerial image. Also provided is a method for simulating an aerial image from pattern specifications of a mask and a position measuring device for carrying out the method.