A DIELECTRIC PROPERTY ANALYSIS OF FERROELECTRIC THIN FILM USING TERAHERTZ TIME-DOMAIN SPECTROSCOPY

ABSTRACT

This paper presents complex dielectric properties of ferroelectric BSTO thin film, deposited on MgO substrate by pulsed laser deposition, in the frequency range of 0.5 ∼ 3.0 THz using terahertz time-domain spectroscopy (THz-TDS). In order to extract complex dielectric properties of the thin film, multiple reflections within the thin film were considered and an error function between the calculated and measured data was introduced. The real part of the dielectric constant of the BSTO thin film was less than 170 and the dielectric loss tangent of the BSTO thin film varied between 0.9 and 3.0. All values of an error function were less than 7 × 10^{− 4} in the measured frequency ranges. The analysis method using THz-TDS enables us to find out complex dielectric properties of ferroelectric thin film exactly.

keyword:

• Complex dielectric properties
• Ferroelectric BSTO thin film
• Terahertz time-domain spectroscopy (THz-TDS)
• Multiple reflections
• Error function

ACKNOWLEDGMENTS

This work was supported by the IT R&D program of MIC/IITA [2007-S005-02, Development of THz-wave oscillation/modulation/detection module and signal source technology].