| 摘要 |
PURPOSE:To enable the automatic inspection and the high speed inspection of a multilayer pattern by correcting a change in the speed of an X-Y stage to detect a specific region on the pattern to be inspected and positioning the pattern with a high accuracy. CONSTITUTION:The position of an X-Y stage 11 in an X direction is detected by a position detector, which produces a timing signal for every displacement of the stage 11 by a constant distance and the timing signal is supplied to an irradiated light quantity storing type image sensor 17 as a start signal. At this time, though the period of the start signals is changed by the effect of a change in the speed of the X-Y stage, since the period is equal to an incident light quantity storing time of the sensor 17, a gradational image from which the effect of a change in speed is removed by normalizing the output of the sensor 17 by said time is detected in synchronism with the position of stage 11. Thus, a specific pattern on a chip is detected and a timing for taking in the detected pattern into an image memory 21 is controlled. As a result, a chip arrangement error in an X-Y direction is corrected and the gradational image in synchronism with the position of the chip is stored in the image memory 21. Thus, a multilayer pattern is detected with a high accuracy and a visual inspection is automated. |
