| 摘要 |
PURPOSE:To align the different step sizes by reading the central coordinates of the using dies aligned with the step sizes of A and B, and moving the stage by the difference in said step sizes. CONSTITUTION:In a 4-inch wafer, if the step of X and Y is 8mm., the chip (the using die) on the right of the wafer is defined at the 9th column and the 9th row. Cross marks 5 are formed at the center of a reference using die 3 and at the center of a parther die 4 which is located at the position separated by a length l from the center of the die 3 to the pattern to be aligned. If the chiop size to be copied is such that X=5.1mm. and Y=7.1mm., the using die is set at the 10th column and the 14th row. In this case, the coordinates of the using die are separated from the aligning cross by X=-0.4mm. and Y=2.2mm. as a result of the calculation and exceeds the imaging scopes of microscopes 6 and a TV monitor 7. Therefore, the stage is moved by -0.4mm. and 2.2mm., and the cross mark 5 and the pattern to be aligned 8 are aligned in the monitor 7. In this method, the highly accurate alignment can be readily accomplished. |
