| 摘要 |
PURPOSE:To detect a pattern defect at a high speed and at a high accuracy with a simple construction by receiving an output signal of a signal processing circuit to determine a change in the distribution of the intensity of the reflected light with respect to an intensity distribution of a sheet-shaped beam irradiating a pattern surface to be measured. CONSTITUTION:A pattern 16 to be measured from which a defect is detected is irradiated with a sheet-shaped beam having a shape according to the size of the pattern with an objective lens 115. The light reflected on the pattern 16 is reversed through an incident optical path to be changed in the course with a beam splitter 11 and condensed with a condenser lens 120 to be received with a line sensor 17. In a signal processing 18, a video signal 170 to be outputted from the sensor 17 is detected and undergoes an A/D conversion and a slice level intensity is determined to perform a binary coding processing. Then, a pattern defect judging section 19 detects a change in the intensity distribution of the reflected light is detected from a binary coding signal 180 with respect to the intensity distribution of an irradiation beam thereby judging the type and size of a pattern defect, the position of the defect and the like. |
