Abstract: In order to determine a production aerial image of an object to be measured as a result of an illumination and imaging with illumination and imaging conditions of an optical production system, firstly a measurement aerial image of the object to be measured is captured. This is carried out with illumination and imaging conditions of an optical measurement system, which conditions include a predefined measurement illumination setting. Data of the measurement aerial image are generated during the capturing. An object structure of the object to be measured is reconstructed from the data of the captured measurement aerial image by use of a reconstruction algorithm. Data of the reconstructed object structure are generated during the reconstructing. A production aerial image is simulated from the data of the reconstructed object structure with the illumination and imaging conditions of the optical production system.

Abstract: For determining a structure-independent contribution of a lithography mask to a fluctuation of the linewidth, recorded 2D intensity distributions (15zi) of an unstructured measurement region of a lithography mask are evaluated in a spatially resolved manner.

Abstract: For determining a focus position of a lithography mask (e.g., 5), a focus stack of a measurement region free of structures to be imaged is recorded and the speckle patterns of the recorded images are evaluated.

Abstract: Determining an imaging aberration contribution of an imaging optical unit for measuring lithography masks involves firstly focus-dependently measuring a 3D aerial image of the imaging optical unit as a sequence of 2D intensity distributions in different measurement planes in the region of and parallel to an image plane of an imaging of an object by use of the imaging optical unit. A spectrum of a speckle pattern of the 3D aerial image is then determined by Fourier transformation of the measured 2D intensity distributions having speckle patterns. For a plurality of spectral components in the frequency domain, a focus dependence of a real part RS(z) and an imaginary part IS(z) of said spectral component is then determined.

Abstract: For determining a structure-independent contribution of a lithography mask to a fluctuation of the linewidth, recorded 2D intensity distributions (15z1) of an unstructured measurement region of a lithography mask are evaluated in a spatially resolved manner.

Abstract: Determining an imaging aberration contribution of an imaging optical unit for measuring lithography masks involves firstly focus-dependently measuring a 3D aerial image of the imaging optical unit as a sequence of 2D intensity distributions in different measurement planes in the region of and parallel to an image plane of an imaging of an object by use of the imaging optical unit. A spectrum of a speckle pattern of the 3D aerial image is then determined by Fourier transformation of the measured 2D intensity distributions having speckle patterns. For a plurality of spectral components in the frequency domain, a focus dependence of a real part RS(z) and an imaginary part IS(z) of said spectral component is then determined.

Abstract: For determining a focus position of a lithography mask (e.g., 5), a focus stack of a measurement region free of structures to be imaged is recorded and the speckle patterns of the recorded images are evaluated.