Abstract: A method and a device for determining imaging errors of an optical system in the production of a mask for semiconductor component fabrication, including detecting at least one parameter for the characterization of the mask selecting a stored correction data record from a correction database in a manner dependent on at least one parameter for the characterization of the mask, then determining optical measurable properties of the mask using a measuring system, combining the measurement results of the optical properties with the correction data record associated with the mask in a data processing device, and subsequently storing a measurement data record with the corrected measurement result in a database system. The measurement data record is then used for the correction of imaging errors.

Abstract: A measurement technique for determining the width of a structure on a mask is described. During a focus sweep, the width of the structure on a photomask, and an edge slope thereof or the structure contrast thereof are measured on a scanning electron microscope by controlling a current through a flow in a magnetic lens by a control unit. To determine the best focus, a function is fitted to the measured values for the contrast and the angle of edge inclination and the focus is read off at the extreme value thereof. A further function is adapted to the values, measured in each case as a function of the focus for the structural width, and the functional value relating to the previously determined best focus is determined.