| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide good apparatus or methods for detecting contamination in an optical system, e.g., lithographic system, as well as systems and methods using such contamination detection systems and methods. <P>SOLUTION: A sensor is described for sensing contamination in an application system (400). The sensor (100) includes a capping layer (108). The sensor (100) is adapted so as to cause a first reflectivity change upon initial formation of a first contamination layer on the capping layer (108) when the sensor (100) is provided in the system (400). The first reflectivity change thereby is larger than an average reflectivity change upon formation of a thicker contamination layer on the capping layer (108) and larger than an average reflectivity change upon formation of an equal contamination on the actual mirrors of the optics of the system. <P>COPYRIGHT: (C)2009,JPO&INPIT |
