Indium Tin Oxide Film Characterization at 0.1-20 GHz Using Coaxial Probe Method

• Published in: IEEE access Vol. 3; pp. 648 - 652
• Main Authors: Alwan, Elias A., Kiourti, Asimina, Volakis, John L.
• Format: Journal Article
• Language: English
• Published: Piscataway IEEE 2015; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Antenna measurements; calibration; Coaxial probes; Conductors; Electrical properties; Electrical resistivity; Frequency measurement; Frequency ranges; Indium Tin Oxide; indium tin oxide (ITO); Indium tin oxides; open ended coaxial probe; Optical coatings; Optical films; Optical imaging; Optical properties; Optical reflection; Oxide coatings; Permittivity; Permittivity measurement; Post-production processing; Radio frequency; Reflectance; thin film characterization; Thin films; indium tin oxide (ITO); Calibration; thin film characterization; open ended coaxial probe
• ISSN: 2169-3536; 2169-3536
• DOI: 10.1109/ACCESS.2015.2433062

Indium tin oxide (ITO) is one of the most commonly used optically transparent conductors in applications, such as electro-optic antennas, displays, and optical coatings. However, their RF frequency-dependent electrical properties have not been reported in the literature. In this paper, we present measurements of the electrical properties (permittivity and conductivity) of ITO films in the 0.1-20-GHz frequency range. Measurements were carried out using an in-house open-ended coaxial probe technique employing a one-port reflection coefficient. As usual, calibration and numerical post-processing is needed to extract the electrical properties of the ITO film placed on a 0.5-mm-thick Eagle glass. The measured conductivity was on the order of 10 5 throughout the frequency range, and the real and imaginary parts of the permittivity were on the order of 10 6 at lower frequencies and 10 5 at higher frequencies.