SYNTHESIS, PROPERTIES, AND MOLECULAR-STRUCTURE ANALYSIS OF SIO2 THIN-FILMS PREPARED BY SOL-GEL METHOD

SiO2 thin films were prepared by the sol-gel method. The properties of the films such as film thickness, etching rate in hydrofluoric acid, Vicker's hardness, and the effect of the thermal treatment on the mole cular structure were investigated. As a result, it was found that the etching resistance and hardness were improved as the treatment tempera ture increased. These changes in the properties were related to the de nsity and water content in the film. The molecular structure analysis by the Si-29 solid-state NMR and Raman spectroscopy revealed that the unstable distorted Si-O-Si bonds formed in the solution were broken an d stable straight Si-O-Si bonds were formed during the high-temperatur e treatment. As the number of the stable Si-O-Si bonds increases, the hardness and density of the films increases.