INTERFERENCE MEASURING APPARATUS AND MEASURING METHOD

摘要

PROBLEM TO BE SOLVED: To improve measurement accuracy in an interference measuring apparatus using the interference of light.

SOLUTION: The interference measuring apparatus is constituted of a light source 10 for radiating supercontinuum light (SC light); an optical fiber coupler 11 for dividing the SC light into measuring light and reference light; a dispersion compensation element 12; a drive unit 13 for moving the dispersion compensation element 12; and a light-receiving means 14 for measuring the interference waveform between the measuring light and the reference light. A measurement object 15 to be measured is an Si substrate having a thickness of 800 μm. The dispersion compensation element 12 is an Si substrate having a thickness of 780 μm. In other words, the dispersion compensation element 12 is made of the same material as that of the measurement object 15 and is thinner by 20 μm than the measurement object 15. Interference by reflection at the back surface of the measurement object 15 and the back surface of the dispersion compensation element 12 has a narrow peak width since wavelength dispersion is mostly negated to improve measurement accuracy of peak positions. As a result, measurement accuracy in temperature and others is improved.

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