Abstract: A method for evaluating a feature. The method includes receiving an image of the feature and determining respective coordinates of a plurality of points on an edge of the feature in the image. A figure having a non-circular and non-linear shape is fitted to the plurality of points, and respective distances between the plurality of points and the figure are determined. A roughness parameter for the feature is computed using the respective distances. The method may be applied in the analysis of critical dimensions (CD) of integrated circuits and, particularly, in the measurement of the edge roughness of their features and components as imaged using electron scanning microscopy (SEM).

Abstract: A system that includes: (a) a mask manipulator, that is arranged to: receive an opaque EUV pod that encloses a EUV mask, extract, in a highly clean environment, the EUV mask from the outer pod and the inner pod of the EUV pod, and cover an upper face of the EUV mask with protective cover that is at least partially transparent to DUV radiation; (b) a scanner, arranged scan the EUV mask, using DUV illumination while maintaining in the scanner an environment that has a cleanliness level that is below a tolerable EUV mask cleanliness level; and a transport system arranged to transport the EUV mask and the protective cover between the scanner and the mask manipulator.

Abstract: The invention provides a method and apparatus for automatically aligning a beam of charged particles with an aperture. Thereby, a defocusing is introduced and a signal calculated based on an image shift is applied to a deflection unit. Further, a method for correction of astigmatism is provided. Thereby, the sharpness is evaluated for a set of frames generated whilst varying the signals to a stigmator.

Abstract: The invention provides a method for automatically aligning a beam of charged particles with an aperture. Thereby, a defocusing is introduced and a signal calculated based on an image shift is applied to a deflection unit. Further, a method for correction of astigmatism is provided. Thereby, the sharpness is evaluated for a set of frames generated whilst varying the signals to a stigmator.

Abstract: The invention provides a method for automatically aligning a beam of charged particles with an aperture. Thereby, the beam is defelcted to two edges of the aperture. From the signals required to obtain an extinction, a correction deflection field is calculated. Furter, a method for automatically aligning a beam of charged particles with an optical axis is provided. Thereby a defocusing is introduced and a signal calculated based on an introduced image shift is applied to a deflection unit. Further, a method for correction of the astigmatism is provided. Thereby the sharpness is evaluated for a sequence of frames measured whilst varying the signals to a stigmator.