Ellipsometer and apparatus for inspecting semiconductor device including the ellipsometer

An ellipsometer comprising:

• a polarizing optical element unit configured to separate reflected light into two linear polarization components, the two linear polarization components having polarization directions that are orthogonal to each other, the reflected light being light reflected from a measurement surface of a sample when illumination light comprising linear polarization illuminates the measurement surface of the sample;
• with respect to the two linear polarization components, an analyzer unit configured to transmit components in a direction, which is different from each of the polarization directions of the two linear polarization components, to make the two linear polarization components interfere with each other, and form an interference fringe in a form of a stripe;
• an image detector configured to detect the interference fringe;
• and
• processing circuitry configured to calculate ellipsometry coefficients Y and A from the detected interference fringe,
• wherein the polarizing optical element unit comprises a plurality of Nomarski prisms.

An apparatus for inspecting a semiconductor device, the apparatus comprising:

• an ellipsometer;
• a stage configured to receive thereon the semiconductor device as an inspection target;
• and
• an environment chamber configured to isolate a part of the ellipsometer and the stage from an external environment,
• wherein the ellipsometer comprises,
• a polarizing optical element unit configured to separate reflected light into two polarization components, the two polarization components having polarization direction that are orthogonal to each other in a radial direction with respect to an optical axis of an optical system of the reflected light, the reflected light being light reflected from a measurement surface of a sample when illumination light illuminates the measurement surface of the sample, the illumination light comprising at least one of linear polarization, circular polarization, or elliptical polarization;
• with respect to the two polarization components, an analyzer unit configured to transmit components of in a direction, which is different from the polarization direction of each of two polarization components, to make the two polarization components interfere with each other and to form an interference fringe in a form of a concentric circle;
• an image detector configured to detect the interference fringe;
• and
• processing circuitry configured to calculate ellipsometry coefficients Ψ and Δ from the detected interference fringe.