Polarization measuring device and method of fabricating semiconductor device using the same

A polarization measuring device comprising:

• a stage on which a measurement target is provided;
• a light source assembly configured to emit incident light;
• a first polarimeter configured to polarize the incident light;
• a second polarimeter configured to polarize reflected light reflected from the measurement target that is irradiated by the incident light;
• a filter assembly configured to remove noise from the reflected light;
• and
• a detector configured to receive the reflected light and measure an intensity of the reflected light and a phase of the reflected light,
• wherein the first polarimeter comprises a photoelastic modulator configured to change a phase of the incident light, and
• wherein the filter assembly comprises a lock-in amplifier configured to selectively acquire a signal of reflected light of a certain frequency.

A method of fabricating a semiconductor device, the method comprising:

• generating reflected light by reflecting light from a measurement target that is irradiated by linearly polarized incident light;
• filtering the reflected light;
• and
• detecting the reflected light by receiving the reflected light,
• wherein the incident light includes first incident light and second incident light, a phase of the first incident light being different from a phase of the second incident light,
• wherein the filtering of the reflected light comprises selectively filtering a signal of a modulation frequency f of a photoelastic modulator and a signal of a frequency 2f, which is twice the modulation frequency f of the photoelastic modulator, and
• wherein the detecting of the reflected light comprises receiving reflectivity information of the reflected light.