Measuring apparatus, measuring method, and storage medium

A measuring method using a light source configured to emit measurement light having a wavelength that transmits through a measurement target object, a spectrometer configured to measure a spectroscopic spectrum waveform of light in which the measurement light is reflected from a measurement target object, and a storage device configured to store a first correction table including a measurement value of a thickness or a temperature and a true value of the thickness or the temperature and a second correction table including a measurement value of a phase angle and a true value of the thickness or the temperature, the measuring method comprising:

• performing Fourier transform of the spectroscopic spectrum waveform measured by the spectrometer;
• calculating a thickness or a temperature of the measurement target object as a first measurement value based on an amplitude peak position of the waveform after the Fourier transform;
• calculating a phase angle before unwrapping as a second measurement value based on an amplitude peak position of the waveform after the Fourier transform;
• extracting a plurality of first true value candidates corresponding to the first measurement value from the first correction table;
• extracting a plurality of second true value candidates corresponding to the second measurement value from the second correction table;
• and
• outputting, as a thickness or a temperature of the measurement target object, a value based on a first true value candidate and a second true value candidate that are same or closest among the extracted first true value candidates and the extracted second true value candidates.

A storage medium storing a program using a light source configured to emit measurement light having a wavelength that transmits through a measurement target object, a spectrometer configured to measure a spectroscopic spectrum waveform of light in which the measurement light is reflected from a measurement target object, and a storage device configured to store a first correction table including a measurement value of a thickness or a temperature and a true value of the thickness or the temperature and a second correction table including a measurement value of a phase angle and a true value of the thickness or the temperature, wherein

• the program is configured to:
• perform Fourier transform of the spectroscopic spectrum waveform measured by the spectrometer;
• calculate a thickness or a temperature of the measurement target object as a first measurement value based on an amplitude peak position of the waveform after the Fourier transform;
• calculate a phase angle before unwrapping as a second measurement value based on an amplitude peak position of the waveform after the Fourier transform;
• extract a plurality of first true value candidates corresponding to the first measurement value from the first correction table;
• extract a plurality of second true value candidates corresponding to the second measurement value from the second correction table;
• and
• output, as a thickness or a temperature of the measurement target object, a value based on a first true value candidate and a second true value candidate that are same or closest among the extracted first true value candidates and the extracted second true value candidates.