Microwave Annealing Effects of Indium-Tin-Oxide Thin Films: Comparison with Conventional Annealing Methods

In this study, an optimized post-deposition heat treatment method is investigated to improve the electrical, optical, and structural properties of indium-tin-oxide (ITO) thin films applied to transparent electrodes in next-generation displays. In order to improve the properties of ITO thin films, heat treatment is performed using conventional thermal annealing (CTA), rapid thermal annealing (RTA), and microwave annealing (MWA). To evaluate the effect of MWA on the ITO thin film, the electrical, optical, and structural characteristics of the thin film are analyzed and compared with those of the films annealed by traditional CTA and RTA. The results show that the electrical and optical characteristics of the ITO thin film improve with the increase in microwave power. In particular, the sheet resistance of the ITO thin film reduces to 4 × 102 Ω sq−1, despite the microwave power of 250 W and short heat treatment duration of 2.5 min by MWA. In addition, the optical transmittance of the ITO thin film in the visible region increases to 89.5%, superior to the transmittance before heat treatment of 87.5%.