Optical measurement apparatus, measuring method using the same, and method of fabricating semiconductor device using the same

An optical measurement apparatus comprising:

• a light source unit configured to generate and output light;
• a polarized light generating unit configured to generate polarized light from the light;
• an optical system configured to generate a pupil image of a measurement target, using the polarized light;
• a self-interference generating unit configured to generate multiple beams that are split from an incident beam of the pupil image;
• and
• a detecting unit configured to detect a self-interference image generated by interference of the multiple beams with each other.

An optical measurement apparatus comprising:

• a light source unit configured to generate and output light;
• a polarized light generating unit configured to generate polarized light from the light;
• a first beam splitter configured to:
• direct the polarized light toward a measurement target, and
• emit a reflected light reflected from the measurement target;
• an objective lens configured to:
• condense the polarized light on the measurement target, and
• provide an incident beam of a pupil image of the measurement target from the reflected light;
• a self-interference generating unit configured to generate multiple beams that are split from the incident beam of the pupil image;
• and
• a first detecting unit configured to detect a self-interference image generated by interference of the multiple beams with each other,
• wherein the self-interference generating unit includes:
• a first beam displacer and a second beam displacer that generate the multiple beams,
• a first wave plate interposed between the first beam displacer and the second beam displacer, and
• an analyzer configured to filter a polarization state of the multiple beams.