| 摘要 |
PURPOSE:To obtain an aligner which provides highly accurate alignment and a high yield by a method wherein the relative position between a mask and a wafer is aligned from a separation state to a contact state by shifting an object lens. CONSTITUTION:An object lens 6 is vertically driven by a control circuit 7 of the lens 6. The output of a CCD shows a waveform 18' with a small output at the time of defocusing and shows a waveform 18 with a peak at the time of focusing. The peak value is detected to position the lens 6. A mask 1 and a wafer 3 are shifted by a control circuit 5 to the position where the mask 1 and the wafer 3 are parallel to each other and have a separation gap (w) between each other. The alignment mark 101 of the wafer 3 is aligned with the center of the alignment mark 100 of the mask 1. After the wafer 3 is made to ascend and brought into contact with the mask 1, the alignment discrepancy is obtained by optical detection systems 50 and 51 and discrepancy is confirmed to be within the allowable range. With this constitution, an aligner which provides highly accurate alignment and a high yield can be obtained. |
