Patent ID: 8154595

Claim:
A device for automatic detection of a possible incorrect measurement during the determination of the position and/or dimension of a structure on a substrate, the device comprises: at least one reflected light illumination apparatus and/or a transmitted light illumination apparatus; at least one imaging optical system and one detector of a camera for imaging the structures on the substrate; a first program portion linked to the detector of the, camera, wherein said detector is provided for determining the position and/or dimension of the structure on the substrate and wherein the device determines and records a plurality of measurement variables M j , j belonging to the group of {1, . . . , L}, from which at least one variable G can be determined; and a second program portion linked to the detector of the camera, wherein said second program portion calculates an analysis of the measurement variables M j with regard to a possible incorrect measurement, wherein the possible incorrect measurement is determined by examining a plurality of quality factors Q i , i belonging to the groups of {1, . . . , N}, wherein the quality factors Q i can be determined from the measurement variables M j , wherein each quality factor Q i is determined according to a rule fi from the measurement variables M i : Q i =f i (M 1 , . . . , M L ), and wherein the rule f i is selected such that the associated quality factor Q i correlates to the variable G.