| 摘要 |
PURPOSE:To reduce the positioning time, by forming a V-shaped detection mark on an object to be measured and thus securing the detection for the shift of position in both X and Y directions just through a scanning action. CONSTITUTION:A V-shaped detection mark 1 is formed on a semiconductor wafer. At the same time, a reference scan (starting point Q and scanning line 4) in case when the wafer is at a prescribed position to be positioned and before detecting actual shift of position, and thus a reference scanning signal 4 is obtained. If the scan to detect the shift of position is started at R for instance, the scan 2 produces a scenning signal 5. As a result, the shift of Y direction is detected by a comparison between the spaces G and F of both pulses, and the shift of X direction can be detected by a comparison between the center positions O' and O'' of both pulses respectively. |
