An inspection system includes a main support die configured to receive a target specimen; an auxiliary support die adjacent to the main support die and configured to receive a reference specimen; a cleaning device configured to remove contaminants from the reference specimen; an objective lens unit configured to direct light to main support die from a light source adjacent to the objective lens unit; a spectroscope between the objective lens unit and the light source; a detector adjacent to the objective lens unit; an imaging device between the objective lens unit and the detector; and a computer system in communication with the detector.