| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an inspection device capable of detecting relatively large-sized defects with high sensitivity as well as fine defects whose amount of change in height or depth is equal to or less than 1 nm. <P>SOLUTION: The inspection device includes: an objective lens 20 for projecting an illumination beam from a illumination source 1 towards a substrate 21 to be inspected; a differential interference optical system 16 for converting the incident illumination beam into a first and a second sub-beams which have coherence between each other, and combining the sub-beams reflected on the surface of the substrate, and emitting an interfering beam including phase difference information related to the height or the depth of the substrate surface; and photodetection means 28 for receiving the emitted interfering beam. A retardation amount of the differential interference optical system is set in such a manner that a phase difference of (2m+1)π or close to it between the first and the second sub-beams is formed, when m is zero or a positive integral number, and the substrate surface is scanned by the illumination beam in an inspection state where a luminance level of a background of an output signal output from the photodetection means is almost zero. <P>COPYRIGHT: (C)2012,JPO&INPIT |
