CALIBRATION APPARATUS AND METHOD OF CALIBRATING RADIATION SENSOR IN LITHOGRAPHIC APPARATUS

摘要

PROBLEM TO BE SOLVED: To provide a calibration apparatus and a method of calibrating a radiation sensor in a lithographic apparatus.;SOLUTION: A calibration apparatus 1 is provided for calibrating a radiation sensor RS in a lithographic apparatus. The calibration apparatus includes a window 3 formed of a substantially radiation-transparent material for allowing radiation to pass therethrough to reach the radiation sensor. A first reference sensor 6 is located behind the window having an active surface abutting the window for measuring the intensity of the radiation that passes through the window. A second reference sensor 8 is located at a short distance behind the window having an active surface facing the window. The second reference sensor measures the intensity of the radiation that passes through the window, a first contamination layer 12 formed on the window, and a second contamination layer 13 formed on the active surface of the second reference sensor. The radiation sensor can be calibrated by combining measurements from the first and the second reference sensors.;COPYRIGHT: (C)2006,JPO&NCIPI