APPARATUS FOR MEASURING THICKNESS OF THIN FILM, MEASURING SYSTEM COMPRISING THE SAME, AND METHOD FOR MEASURING THICKNESS OF THIN FILM

摘要

A thin film thickness measuring device, a system including the same, and a thin film thickness measuring method are provided. The thin film thickness measuring device comprises: a signal detecting unit configured to detect an electric field signal with respect to reflecting light reflected from a thin film; an FFT operation unit configured to perform fast Fourier transform (FFT) in the electric field signal to separate a DC component and an AC component of the electric field signal from each other; an IFFT operation unit configured to preform inverse FFT by receiving only the AC component of the electric field signal and to extract a phase value with respect to the received AC component; and a thickness operation unit configured to operate a thickness of the thin film by using the phase value. The electric field signal comprises: a first electric field signal with respect to first reflecting light reflected from the thin film before a process and a second electric field signal with respect to second reflecting light reflected from the thin film after the process.