| 摘要 |
PURPOSE:To provide the device which can detect the dust on an original plate. CONSTITUTION:This device consists of a laser beam sweeping means for executing sweeping in either of an X or Y direction by changing the angle of a mirror 28 provided in a laser beam path 2, a moving means for executing the laser beam sweeping in the other direction by moving either of the original plate or a laser device, means 15, 16, 26, 27 for detecting the end point of the movement for sweeping provided in correspondence in the position of the image of the original plate, a control means 19 for operating the moving means on knowing of the end point of the movement by the means for detecting the end point of the movement for sweeping and a photodetecting means 3 for detecting the scattered light generated by the dust on the original plate. The surface of the original plate 29 in the semiconductor production stage for IC, LSI, etc., is irradiated and swept by the laser beam from the laser device 1, by which the dust on the surface is detected. |
