| 摘要 |
PROBLEM TO BE SOLVED: To obtain a measuring apparatus for a level difference which can measure a level difference of a wafer precisely when an operative portion and a non-processed section are remarkably different in area and the wafer vibrates during measurement. SOLUTION: A sensing light 6 from a light source 2 becomes parallel light 61 by a collimator lens 5. After passing a spatial filter 8, the parallel light 61 is condensed on a wafer 1 in which a working trench or the like is formed by a condenser lens 4. The light condensed on the wafer 1 is reflected by the wafer 1. The reflected light 63 is made parallel light 64 by a collimator lens 51 and enters a detector 3. A working state of the wafer 1 is detected from intensity variation of the reflected light 64. As the spatial filter 8, a form which is subjected to Fourier transformation of the rectangle is used. COPYRIGHT: (C)2004,JPO
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