| 摘要 |
PURPOSE:To reduce the time necessary for position alignment, by forming the wafer or the mask with the suitable quantity and sequence corresponding with the distribution of initial positions of wafers after pre-alignment. CONSTITUTION:The input means 11 inputs the distribution of initial positions of wafers, while the calculation output means 12 calculates quantity and sequence to move the wafer according to the input data through the input means 11. These data of the calculation output means 12 are delivered to the moving means 13 which moves the wafer according to them. The measuring means 14 measure the relative displacement between the mask and the wafer. The distance necessary to move the wafer so that the alignment mark may cross the scanning line of laser widely varies in accordance with the shape of distribution. The best sequence to move the wafer also differs and the necessary time becomes short in case of small distance. Consequently, the alignment time can be minimized by moving the wafer in accordance with the distribution state of the initial positions. |
