| 摘要 |
PURPOSE:To accurately locate a pattern on a wafer without a fear of causing a flaw by presetting the reference surface of wafer for positioning and providing a non-contact type distance detector at the area isolated from such reference surface. CONSTITUTION:A wafer for calibration is placed on a table 3 and the table 3 is shifted to the right and left and also vertically. Thereby, the area of calibration wafer opposing to the non-contact type distance detector 14 is caused to match the reference surface A. At this time, a detecting output is stored in a controller 15. Next, a wafer 1 to be processed is placed on the table 3, a pulse motor 11 is operated by the controller 15. Thereby, a support table 4 is driven vertically and the motor 11 is caused to stop at the point where an output of detector matches the stored detection output. Thereby, the wafer 1 accurately matches the reference surface A. In above operations, since the wafer 1 does not caused to be in contact with the detector 14, it does not receive any damage due to contactness. |
