| 摘要 |
PURPOSE:To detect the position of a mark for position alignment, which is formed on the surface of a semiconductor wafer even if the optical axis of a microscope is inclined with respect to the surface of the semiconductor wafer. CONSTITUTION:The continuous-spectrum light emitted from a light source 41 is made to pass through an objective lens 21 and cast on a step-shaped positioning mark, which is formed on the surface of a semiconductor wafer 10. The reflected light from the semiconductor wafer 10 is cast into an image pickup device 50 through the objective lens 21, and the image of the positioning mark 11 is picked up. The picked-up image is processed, and the position of the positioning mark 11 is detected in this mark-position detecting device. A band-pass filter 43, which flattens the spectrum of light approximately, is arranged at the position of the image formed with an image focusing lens 42 of the continuous light source 41. |
