| 摘要 |
PURPOSE:To improve the precision of position detection by reducing the effect of the secular change of an equipment by detecting the interval between the two position detection devices and focussing conditions when substrates to be exposed are replaced. CONSTITUTION:When each chip of a wafer 23 is finished to be exposed, a control unit 30 gives a movement command signal for moving a stage 21 to a water transfer position to a driving unit 29 and when the stage 21 is detected to be at the transfer position by the signal from an interferometer 28 which monitors the coordinates of the stage 21, the stage 21 is stopped. A driving control unit 27 is given a command signal for replacing the wafers and as a result, an arm driving unit 26 drives a wafer arm 25 and the already exposed wafer 23 is replaced with a non-exposed water 24. Meanwhile, the control unit 30 detects a relative position and a focussing position by using a time when the already exposed water 23 is removed from the stage 21 and the non-exposed wafer 24 is mounted on the stage 21. This prevents the deterioration of the precision of an equipment due to a secular change. |
