| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a thickness irregularity measurement device capable of reducing measurement errors caused by thermal expansion of a substrate and measuring thickness irregularity of an object under measurement.SOLUTION: A thickness irregularity measurement device 100 includes; a light source 101; light beam splitting means 102a which splits light emitted by the light source into a first light beam which is measurement light, and a second light beam which is reference light; first light guide means which causes the first light beam to be reflected on a front surface S1 of an object under measurement W and then guides the reflected light to a back surface S2 of the object under measurement W, so that the reflected light is reflected at a position right opposite a point of reflection on the front surface S1; a polarizing plate 106 which lets the first light beam after being reflected by the back surface S2 of the object under measurement W interfere with the second light beam, or the reference light, to generate interference fringes; and interference fringe detection means 107 which detects the interference fringes generated by the polarizing plate 106.</p> |
