Abstract: A method of manufacturing a photomask includes forming a mask pattern with a critical mask feature on a photomask. Shape information which is descriptive for an outline of the critical mask feature is obtained from the photomask. The shape information contains position information identifying the positions of landmarks on the outline relative to each other. The landmarks may indicate local curvature extrema, points of inflexion, sharp bends in the curvature and/or local curvature-change maxima in the outline of the mask feature, respectively. The shape information may enable a shape metrology which is not completely based on rectangular approximations of mask features.

Abstract: An EUV mask set and method of manufacturing is disclosed. In one embodiment, a set of EUV mask blanks is inspected to obtain information about defects in each of the EUV mask blanks. From the obtained information, a set of complementary functional portions is determined, wherein each functional portion is assigned to one of the EUV mask blanks and does not contain any of the defects. The functional portions of the EUV mask blanks of the EUV mask blank set complement one another to form a virtual image area corresponding in size to image areas of the EUV mask blanks. A predefined mask pattern is provided on the EUV mask blanks. Information identifying position and shape of the functional portions is used to control an illumination process for imaging the predefined mask pattern onto a target.

Abstract: An EUV mask set and method of manufacturing is disclosed. In one embodiment, a set of EUV mask blanks is inspected to obtain information about defects in each of the EUV mask blanks. From the obtained information, a set of complementary functional portions is determined, wherein each functional portion is assigned to one of the EUV mask blanks and does not contain any of the defects. The functional portions of the EUV mask blanks of the EUV mask blank set complement one another to form a virtual image area corresponding in size to image areas of the EUV mask blanks. A predefined mask pattern is provided on the EUV mask blanks. Information identifying position and shape of the functional portions is used to control an illumination process for imaging the predefined mask pattern onto a target.