Patent ID: 6891627

Claim:
A system configured to determine at least two properties of a specimen during use, comprising: a stage configured to support the specimen during use; a measurement device coupled to the stage comprising: an illumination system configured to direct energy toward an upper surface of the specimen during use and to direct energy toward a bottom surface of the specimen during use; and a detection system coupled to the illumination system and configured to detect energy propagating from the upper surface of the specimen during use and to detect energy propagating from the bottom surface of the specimen during use, wherein the measurement device is configured to generate one or more output signals in response to the detected energy during use; and a processor coupled to the measurement device and configured to determine a first property, a second property, and a third property of the specimen from the one or more output signals during use, wherein the first property comprises a critical dimension of the specimen, wherein the second property comprises overlay misregistration of the specimen, and wherein the third property comprises a presence of defects on the bottom surface of the specimen.