Fujikawa Shigenori, Takaki Rie, Kunitake Toyoki
Topochemical Design Laboratory, Innovative Nanopatterning Laboratory, RIKEN, Wako, Saitama 351-0198, Japan.
Langmuir. 2006 Oct 10;22(21):9057-61. doi: 10.1021/la061830e.
We report herein fabrication of arrays of sub-20-nm silica walls via photolithography and the surface sol-gel process. A photolithographically fabricated line template on a silicon wafer was coated with a silica nanolayer using the surface sol-gel process, and then the topmost portion of the silica layer and the template were successively removed using CHF(3) and oxygen plasma, respectively, leaving the sidewalls of the silica layers remaining on the substrate. These walls were fully self-supporting, and the thicknesses of silica wall were 6, 8, and 12 nm at 20, 30, and 60 cycles, respectively. The height/width ratio of the wall was 38 at the 30-cycle coating. This ratio is surprisingly high when compared to that of the conventional photolithography processes. Successive formation of the silica, polymer, and silica layers yielded a trilayer sidewall, and the spacer polymer layer could be selectively removed to form a doubled sidewall. Size reduction and proliferation of sub-20-nm silica wall was thus achieved. The reported method is simple and cost-efficient and opens a gateway to further miniaturization of nanostructures.
我们在此报告通过光刻和表面溶胶 - 凝胶工艺制备亚20纳米二氧化硅壁阵列的方法。在硅片上通过光刻制造的线条模板使用表面溶胶 - 凝胶工艺涂覆二氧化硅纳米层，然后分别使用CHF₃和氧等离子体依次去除二氧化硅层的最顶部部分和模板，使二氧化硅层的侧壁留在基板上。这些壁完全自支撑，在20、30和60个循环时，二氧化硅壁的厚度分别为6纳米、8纳米和12纳米。在30次循环涂覆时，壁的高/宽比为38。与传统光刻工艺相比，该比例出奇地高。依次形成二氧化硅、聚合物和二氧化硅层产生了三层侧壁，并且间隔聚合物层可以被选择性地去除以形成双层侧壁。从而实现了亚20纳米二氧化硅壁的尺寸减小和增殖。所报道的方法简单且成本效益高，为纳米结构的进一步小型化开辟了道路。
