Carrier lifespan measurement method and carrier lifespan measurement device

A carrier lifetime measurement device for measuring a lifetime of carriers in a measurement target object, the carrier lifetime measurement device comprising:

• a first light source configured to generate measurement light;
• a second light source configured to generate stimulus light;
• a modulator configured to perform intensity modulation of the stimulus light using a plurality of frequencies;
• a photo detector configured to output a detection signal by detecting an intensity of reflected light from the measurement target object or transmitted light through the measurement target object;
• an optical system configured to guide the measurement light and the stimulus light subjected to intensity modulation toward the measurement target object and to guide reflected light from the measurement target object or transmitted light through the measurement target object toward the photo detector;
• and
• an analyzer configured to detect a phase delay of the detection signal with respect to a modulation signal including a frequency in association with a concentration of impurities in a measurement target region of the plurality of frequencies, and to generate image data indicating a distribution of lifetimes of carriers in the measurement target object on the basis of the phase delay.