Mesostructured silica films with a well-ordered Im3m structure and enhanced surface properties can be synthesized by means of cosolvent addition and the optimization of sol aging time. Mesostructured silica films fabricated using ethanol, a commercial solvent, result in wavy surface properties induced by the Marangoni effect irrespective of rotation speed during spin coating. In order to improve the surface roughness, we used an ethanol-acetone mixture as a solvent with a certain molar ratio. Wavy and rough films could be avoided when the acetone molar ratio was optimized. The simultaneous increase of unit cell size and thickness of the film was observed when the amount of cosolvent was increased. The unit cell was also enlarged with sol aging time, and well-ordered mesoporous silica films could be synthesized by controlling the silica sol aging. The dielectric property could be improved by means of cosolvent addition only after the development of a highly ordered mesoporous nature of the film by calcination. The leakage current of the mesoporous silica film could be reduced when the structural ordering and surface roughness were controlled.
Bibliographical noteFunding Information:
The authors would like to acknowledge the financial support from University Research Program supported by Ministry of Information and Communication in Republic of Korea (B1220-0501-0077).
All Science Journal Classification (ASJC) codes
- Physics and Astronomy(all)