HfO2 Thin Films Prepared by Hydrothermal Synthesis

HfO2 sols were prepared by hydrothermal synthesis from HfOCl2 center dot 8H(2)O (precursor). HfO2 thin films were further prepared via a spin coating method. TEM and particle size analyzer were used to characterize the microstructure and particle size distribution of the HfO2 sols. It is found that the particle size in HfO2 sols can be controlled from about 3 nm to 100 nm via changing reaction parameters. The HfO2 and HfO2-PVP thin films were characterized by ellipsometer, atomic force microscope (AFM), and Fourier-transform infrared spectroscopy (FTIR) respectively. The roughness of HfO2-PVP films is less than 0.5 nm and the refractive index is about 1.75. The results show that the laser damage threshold of HfO2 films is higher than 15 J/cm(3) (1064 nm, 1 ns), while the laser damage threshold for HfO2-PVP coatings can be as high as 20 J/cm(3) (1064 nm, 1 ns). The mechanism of the laser damage process of HfO2-PVP coatings was also discussed.