Patent ID: 7528960

Claim:
A method for precision measurement of coordinates of at least one structure on a substrate placed on a stage moveable in X/Y coordinate directions in an interferometric-optical measuring system, the at least one structure on the substrate being imaged onto at least one detector via a measuring objective having an optical axis aligned in a Z coordinate direction, the method comprising the following steps: traversing the stage moveable in the X/Y coordinate directions in such a way that the at least one structure on the substrate is positioned in at least one predefined measuring window of the at least one detector; carrying out a relative movement in the Z coordinate direction at least once, wherein in synchronism to the relative movement in the Z coordinate direction, a plurality of images of the at least one structure are recorded by the at least one detector, and determining a position of the stage in the X and Y coordinate directions also in synchronism to the recording; traversing the stage at least once by a distance in a plane defined by the X and Y coordinate directions, and shifting the at least one predefined measuring window also by the distance; carrying out a further relative movement in a further direction opposite the Z coordinate direction at least once, wherein a further plurality of images of the at least one structure are further recorded by the at least one detector in synchronism to the further relative movement in the further direction, and determining a further position of the stage in the X and Y coordinate directions also in synchronism to the further recording; and determining at least one actual position of the at least one structure from a Z position recorded synchronously to the recorded images of the at least one structure during the relative movement and the further relative movement, and from the position of the stage and the further position of stage determined for each image.