| 摘要 |
PURPOSE:To prevent the contamination due to particles at the time of alignment and the deviation of center position due to the error of wafer diameter, and reduce alignment time. CONSTITUTION:From the movement data of a carrying mechanism (the number of pulses of a pulse motor or the data from an encoder 3) when a wafer 4 is carried, and the edge data of the wafer 4 given by a sensor 1 which data are obtained when the wafer 4 passes and a light is cut off or reflected by the wafer 4, the following are obtained at a time; the data of offset and the rotation amount (the position of a rotation flat) of the present wafer 4 to the position where the wafer 4 is to be set. The alignment of the wafer 4 is performed on the basis of the above data. |
