Characterization and Annealing Effects of Titanium Dioxide Films Prepared by a Sol-Gel Process
Titanium dioxide (TiO2) has received intense interest because of the numerous technical applications. In this work, the TiO2 thin films were deposited on Si substrates by spin coating from a TiO2 solution prepared by a sol-gel method. It was found that the TiO2 film properties strongly depended on the post annealing conditions. X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectrometer (FTIR) were used to investigate the compositional and chemical states of the thermal-treated TiO2 samples. For the TiO2 samples annealed in atmosphere, the contents of -C and -OH bonds increased when the process temperature increased. From XPS measurement, the atomic concentrations of carbon and oxygen in the film are determined to be approximately 46% and 37%, respectively. However, for the samples annealed in oxygen, the contents of -C and -OH bonds were found to decrease when the anneal temperature increased. The concentrations of carbon and oxygen in the film were approximately 11% and 59%, respectively. To further investigate the behavior, the in-depth concentration profile of carbon was measured for the TiO2 samples under different etching time. It was found that the carbon concentration drastically decreased from 11% (surface) to 0.2% (near the interface). The result indicates that the pure TiO2 film could be obtained by sol-gel coating with a suitable annealing process.
Yansheng Yin and Xin Wang
S. Y. Lien "Characterization and Annealing Effects of Titanium Dioxide Films Prepared by a Sol-Gel Process", Advanced Materials Research, Vols. 79-82, pp. 891-894, 2009