| 摘要 |
PROBLEM TO BE SOLVED: To provide an etching monitor apparatus capable of performing highly accurate measurement even when there is a mask area which may generate interference.SOLUTION: The etching monitor apparatus includes: an interference optical system 13 for acquiring reflection interference light including three kinds of interference component signals; a spectral measurement unit 14 for detecting a reflection interference spectrum; an optical path difference analysis unit 51 for calculating optical path difference analysis data for the reflection interference spectrum; an uncorrected B-C interference distance calculation unit 52 for calculating an optical path difference of a peak position from the optical path difference analysis data as an uncorrected B-C interference distance; a correction table unit 53 for calculating and storing relation between a deviation of the optical path difference due to fusion of two interferences and mask thickness; a mask thickness measurement unit 54; a B-C interference distance true value calculation unit 54 for calculating a deviation of the optical path difference from the mask thickness and a correction table and calculating a corrected BC interference distance obtained by correcting the uncorrected B-C interference distance by the deviation of the optical path difference; and an etching depth calculation unit 55 for calculating etching depth from the corrected B-C interference distance and the mask thickness. |
