| 摘要 |
PROBLEM TO BE SOLVED: To provide a calibration method of vacuum ultraviolet region metrological systems using single or a plurality of calibration samples. SOLUTION: A calibration pad 300 is provided, including a plurality of calibration locations 303 and 305. A particular calibration location is used, for example, until the usage is determined as having to be nonpermissible with contamination, and a calibration process moves the calibration pad to different calibration locations. Moving takes place from the location used for the calibration process to other locations temporally. Various criteria are established to determine the timing of moving to other calibration locations. Although it is based on measured reflectance data that one calibration location 305 is indicated as being a "failure", other criteria are also used. For example, the frequency for a certain location being exposed to light can be adopted as a criterion the location is indicative of a failure. Alternatively, accumulated exposures of any location can also be a criterion. Moreover. a plurality of calibration locations arranged on one calibration pad is given prior evaluation, in order to select and remove nonpermissible calibration locations prior to use. COPYRIGHT: (C)2011,JPO&INPIT
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