Nano-scale optical elements by fine patterning of self-assembled monolayers

本计画系关于利用微接触印刷技术制作奈米级光学元件之方法。将烷基硅烷分子涂覆在具有纳米至微米图案的聚二甲基硅氧烷（PDMS）印模上，并将分子转移到玻璃晶片上以形成自组装单层（SAM）。然后，用荧光分子标记分子以增强光学性质。我们使用PDMS作为邮票的材料。印模的图案从硅模具上转移，硅模具是用各向同性刻蚀或电子束（EB）直接光刻制作的。首先，使用具有微尺度线条和空间的印模来验证SAM图案化的可行性。我们在PDMS印模上涂上末端带有氨基的氨基丙基三乙氧基硅烷（APTES），并将印模压在玻璃片上。用荧光染料标记APTES，并在荧光显微镜下观察。通过比较印模和图案化的APTES的线宽来评估图案。对于合适的图案化，压制时间和压力分别为15秒和20克。其次，制备了纳米尺度的光学元件。FITC本身被用作光学元件。将APTES的纳米级图案化和FITC标记相结合，成功实现了纳米级光学元件的制备。使用用亚微米线绘制的插图的PDMS印模，在玻璃晶片上图案化APTES。FITC与图案化的APTES结合。我们成功地观察到荧光分子确实沿着APTES以纳米级的分辨率被图案化，并证实了荧光分子作为纳米级光学元件工作。

This project is on a fabrication method of nano-scale optical elements using micro contact printing (uCP). Alkyl silane molecules were coated on poly(dimethylsyloxane) (PDMS) stamps with nano- to micro-patterns, and transferred the molecules onto a glass wafer to form a self-assembled monolayer (SAM). Then, the molecules were labeled by fluorescent molecules to enhance optical properties. We used PDMS as a material of the stamps. The patterns of the stamps were transferred from silicon molds, which were fabricated with isotropic etching or electron beam (EB) direct lithography.Firstly, stamps with micro-scale lines and spaces were used to confirm the feasibility of SAM patterning. We coated Aminopropyltriethoxysilane (APTES), which has amino group at its terminal, on the PDMS stamps, and pressed the stamp onto glass wafer. The patterned APTES were labeled by the fluorescent dye molecules (FITC), and observed with fluorescent microscope. The pattern was evaluated by comparing the line width of the stamps and the patterned APTES. For suitable patterning, the pressing time and pressure were found to be 15 seconds and 20 grams, respectively.Secondly, nano-scale optical elements were fabricated. The FITC itself was used as an optical element. Combining the nano-scale patterning of APTES and the FITC labeling, we successfully achieved to fabricate nano-scale optical element. Using PDMS stamps of an illustration, which was drawn with sub-micron lines, APTES was patterned on a glass wafer. The FITC were bound to the patterned APTES. We successfully observed that the fluorescent molecules were surely patterned along the APTES with nano-order resolution, and confirmed that the fluorescent molecules work as nano-scale optical elements.