| 摘要 |
PURPOSE:To discriminate the higher part from the lower part of a pattern, by detecting scattered signal media from the difference in a step by a detecting means, which is provided at both sides of the difference in the step, and judging the magnitudes of the detected signal values. CONSTITUTION:For example, when laser 5 is irradiated on the right edge of a pattern 3, the laser 5 is scattered in the directions other than the regular reflecting direction at the edge step. More scattered light is directed to the lower side of the edge step (the side of space, which is the surface of a mask 2) than to the higher part thereof (the side of the pattern 3). Therefore, the detected signal vaue from a second photocell 8 becomes larger than the detected signal value of a first photocell 7. In comparing and judging device 10, the magnitude of the detected signal value of the first photocell 7 and that of the second photocell 8 at the same time are compared. The side, where the photocell that is indicating the large detected signal value is located, is judged to be the lower part, i.e, the space side. The other part, i.e. the higher part, is judged to be the side of the pattern 3. |
