| 摘要 |
<p>PROBLEM TO BE SOLVED: To easily calculate the deformation of a water holder with high accuracy. SOLUTION: In a first state (Fig. 3(A)) where the direction of the wafer holder 25 is set in a prescribed direction, the positional information on a plurality of measurement marks (AMT1-AMT4 and FM1-FM4), arranged on the wafer holder 25 is detected by using a position detecting system 18 and a mark detecting system. In a second state (Fig. 3(B)) where the holder 25 is turned by about 180 deg. from the first state, the position information on the marks (AMT 1-AMT4 and FM1-FM4) is detected by a similar method. Since the position information on the marks (AMT1-AMT4 and FM1-FM4) is calculated in the first state before the holder 25 is turned and the second state after the holder 25 is turned, deformation of the holder 25 caused by the state change from the first state to the second state can be calculated easily and accurately.</p> |
