| 摘要 |
<p>The shape of a periodical unevenness pattern is inspected by a simple device construction, with high precision over a wide range. The surface state of a measurement object region in which a periodical unevenness pattern with a predetermined period is formed is inspected by applying an illuminating parallel light beam to the measurement object region. The method comprises a 1st step in which the illuminating light is applied to the measurement object region obliquely from above, a 2nd step in which reflected light from the measurement object region is focused by an object side telecentric optical system or an image side telecentric optical system which has an optical axis coincident with the incident direction of the illuminating light applied to the measurement object region and whose aperture angle on the object side for one point in the measurement object region is set to a predetermined value, a 3rd step in which the focused image is picked up and luminance data of points in the measurement object region are collected, a 4th step in which the luminance data are subjected to the frequency decomposition in a predetermined direction to obtain frequency data, and a 5th step in which predetermined frequency components are extracted from the frequency data and combined.</p> |
