Abstract: A device for positioning a mask relative to the surface of a wafer with a view to the exposure of the wafer, which includes (i) first positioning structure suitable for holding and moving the mask and the wafer in relation to each other; (ii) imaging structure suitable for producing at least one image of the mask and of the surface of the wafer according to at least one field of view, so as to image positioning marks of the mask and of the wafer simultaneously in the field of view; and (iii) at least one optical distance sensor suitable for producing a distance measurement between the surface of the wafer and the mask in the field(s) of view, with a measurement beam which passes at least partially through the imaging structure.

Abstract: A device for positioning a mask relative to the surface of a wafer with a view to the exposure of the wafer, which includes (i) first positioning structure suitable for holding and moving the mask and the wafer in relation to each other; (ii) imaging structure suitable for producing at least one image of the mask and of the surface of the wafer according to at least one field of view, so as to image positioning marks of the mask and of the wafer simultaneously in the field of view; and (iii) at least one optical distance sensor suitable for producing a distance measurement between the surface of the water and the mask in the field(s) of view, with a measurement beam, which passes at least partially through the imaging structure.