Rotating-element spectroscopic ellipsometer and method for measurement precision prediction of rotating-element spectroscopic ellipsometer, recording medium storing program for executing the same, and computer program stored in medium for executing the same

摘要

Provided are a rotating-element spectroscopic ellipsometer and a method for measurement precision prediction of a rotating-element spectroscopic ellipsometer, a recording medium storing program for executing the same, and a computer program stored in a medium for executing the same, and more particularly, a rotating-element spectroscopic ellipsometer and a method for measurement precision prediction of a rotating-element spectroscopic ellipsometer capable of calculating the measurement precision of the rotating-element spectroscopic ellipsometer based on a theoretical equation on standard deviations of ellipsometric parameters for a sample, a recording medium storing program for executing the same, and a computer program stored in a medium for executing the same.

主权项

1. A rotating-element spectroscopic ellipsometer, comprising:
a light source radiating an incident light toward a sample; a polarization state generator disposed between the light source on a traveling path of the incident light and the sample and controlling a polarized state of the incident light radiated from the light source; a polarization state analyzer receiving reflected light or transmitted light having a changed polarization state while the incident light is polarized by passing through the polarization state generator and then reflected or transmitted by the sample and analyzing a change in the polarization state of the reflected light or transmitted light; a photodetector element receiving the reflected light or the transmitted light passing through the polarization state analyzer and measuring irradiance of the incident light with an electrical signal of a voltage or a current; and a processor operable for calculating measurement precision of the rotating-element spectroscopic ellipsometer based on a theoretical equation on standard deviations of ellipsometric parameters for the sample, wherein the theoretical equation on the standard deviations σ(Q) of the ellipsometric parameters Q for the sample depends on the following equationσ⁡(⟨Q⟩)=[∑j=12⁢Nho+1⁢⁢cQ,Xj2⁢cov⁡(⟨Xj⟩,⟨Xj⟩)+2⁢∑j=12⁢Nho⁢∑k=j+12⁢Nho+1⁢cQ,Xj⁢cQ,Xk⁢cov⁡(⟨Xj⟩,⟨Xk⟩)]1/2, wherein, represent X=(Xj)(2Nho+1)×1 represent a vector of the corrected Fourier coefficients, CQ,Xj=∂Q/∂Xj represents a sensitivity coefficient, cov(Xj,Xk) represents a covariance between the corrected Fourier coefficients, angle brackets (< >) represent a sample mean, and Nho represents an uppermost index value among nonzero alternating current (AC) components of the corrected Fourier coefficient, and wherein a plurality of rotatable elements are disposed in the polarization state generator or the polarization state analyzer and the rotatable element includes a constantly rotating element rotating at a uniform velocity and a scanning element.