| 摘要 |
<p>Positional errors generated due to a stage orthogonal error and mirror distortion are reduced. A CPU (10-2) calculates coordinate errors (?x, ?y), between calculational position coordinates of a plurality of reference points on a reference wafer (W<SUB>0</SUB>) positioned on an XY stage (10-1) and measuring position coordinates (x, y) of the reference points obtained by a laser interferometer (10-4). Based on the calculated coordinate errors (?x, ?y), the orthogonal errors of the XY coordinates are calculated, and errors due to mirror distortion of the interferometer are calculated and stored in a storage apparatus (10-5). At the time of actually inspecting a wafer (W), the CPU (10-2) corrects the measuring position coordinates (x, y) obtained from the laser interferometer (10-4), based on the calculated orthogonal error. Furthermore, based on the calculated error due to mirror distortion, deflection of a beam deflector (10-7) is corrected.</p> |
