FILM THICKNESS MEASUREMENT DEVICE, FILM THICKNESS MEASUREMENT METHOD, FILM THICKNESS MEASUREMENT PROGRAM, AND RECORDING MEDIUM FOR RECORDING FILM THICKNESS MEASUREMENT PROGRAM

摘要

A film thickness measurement device 1 is provided with a light output unit 12 for outputting measurement light L1, a spectroscopic detection unit 13 for spectroscopically detecting light L2 to be detected, and an analysis unit 15 for comparing, against a theoretical reflectance, an actually-measured reflectance for respective wavelengths of a measurement subject S obtained from detection results from the spectroscopic detection unit 13 and analyzing a film thickness of a first film 4 and a film thickness of a second film 5. The analysis unit 15 uses comparison results of actually-measured reflectance and theoretical reflectance for each of the wavelengths from the measurement subject S in a first wavelength range to find a candidate optimal solution for film thickness, and uses comparison results of actually-measured reflectance and theoretical reflectance for each of the wavelengths from the measurement subject S in a second wavelength range different from the first wavelength range to find the optimal solution for film thickness from among candidate optimal solutions.