Tanaka Shunsuke, Nishiyama Norikazu, Oku Yoshiaki, Egashira Yasuyuki, Ueyama Korekazu
Division of Chemical Engineering, Graduate School of Engineering Science, Osaka University, 1-3 Machikaneyama, Toyonaka, Osaka 560-8531 Japan.
J Am Chem Soc. 2004 Apr 21;126(15):4854-8. doi: 10.1021/ja039267z.
Novel mesostructured silica thin films were prepared on a Si substrate by a vapor-phase synthesis. Vapor of tetraethoxysilane (TEOS) was infiltrated into a surfactant film consisting of a poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) triblock copolymer. Nanophase transition from a lamellar structure to a two-dimensional cage structure of a silica-surfactant nanocomposite was found under vapor infiltration. The rearrangement into the cage structure implies high mobility of the silica-surfactant composites in solid phase. The silica thin films have two-dimensionally connected cagelike mesopores and are isotropic parallel to the film surface. The structure of pores of the films is advantageous for next-generation low-k films. The mesoporous structure has a large lattice parameter d of approximately 102 A, silica layer thickness of approximately 58 A, pillar diameter in the middle of approximately 60 A, pore size of approximately 72 A, BET surface area of approximately 729 m(2)/g, and pore volume of approximately 1.19 cm(3)/g. The films synthesized by the vapor infiltration show a lower concentration of residual Si-OH groups compared to the films prepared by a conventional sol-gel method. The films show high thermal stability up to 900 degrees C and high hydrothermal stability. This method is a simpler process than conventional sol-gel techniques and attractive for mass production of a variety of organic-inorganic composite materials and inorganic porous films.
通过气相合成法在硅衬底上制备了新型介孔结构二氧化硅薄膜。四乙氧基硅烷（TEOS）蒸汽渗透到由聚（环氧乙烷）-聚（环氧丙烷）-聚（环氧乙烷）三嵌段共聚物组成的表面活性剂薄膜中。在蒸汽渗透过程中发现了二氧化硅-表面活性剂纳米复合材料从层状结构到二维笼状结构的纳米相转变。重排成笼状结构意味着二氧化硅-表面活性剂复合材料在固相中具有高迁移率。二氧化硅薄膜具有二维连接的笼状介孔，并且与薄膜表面平行呈各向同性。薄膜的孔结构有利于下一代低介电常数薄膜。介孔结构具有大约102 Å的大晶格参数d、大约58 Å的二氧化硅层厚度、中间大约60 Å的柱直径、大约72 Å的孔径、大约729 m²/g的BET表面积和约1.19 cm³/g的孔体积。与通过传统溶胶-凝胶法制备的薄膜相比，通过蒸汽渗透合成的薄膜显示出较低浓度的残余Si-OH基团。这些薄膜在高达900℃时表现出高热稳定性和高水热稳定性。该方法比传统溶胶-凝胶技术更简单，对于大规模生产各种有机-无机复合材料和无机多孔薄膜具有吸引力。
