以十六烷基三甲基溴化铵(CTAB)为模板剂,正硅酸乙酯为无机前驱体,在酸性条件下,采用溶胶-凝胶技术,用蒸发诱导自组装(EISA)工艺制备了二氧化硅透明介孔薄膜.透射电子显微镜图显示热处理后的薄膜具有高度有序的六方相结构孔道;由椭偏仪测得热处理后薄膜的折射率低至1.18,厚度在180nm左右;阻抗分析仪测得薄膜的介电常数为2.14.薄膜经过六甲基二硅胺烷(HMDS)表面修饰后具有良好的疏水性能和热稳定性,作为低介电材料能更好满足工业需求.
Mesoporous silica film was successfully prepared through molecular self-assembly. A precursor sol containing tetraethoxysilane (TEOS), the surfactant template cetyltrimethylammonium bromide (CTAB) and acid catalyst was prepared by sol-gel process. The hexagonal ordered structure of the calcined mesoporous silica film was confirmed by TEM. The refractive index of the directly calcined film is 1.18, the film thickness is about 180 nm, which was performed by spectroscopic ellipsometry measurements. The dielectric constant k of the directly calcined film was 2.14. The hexamethydisilazane (HMDS) vapor treatment is considered to be effective possibly for generating hydrophobic mesoporous silica thin film, and the resulting film will be more useful as low dielectric constant intermetal material in advanced semiconductor devices.