{"id":5239,"date":"2012-07-18T22:29:05","date_gmt":"2012-07-18T22:29:05","guid":{"rendered":"https:\/\/mtlsites.mit.edu\/annual_reports\/2012\/?p=5239"},"modified":"2012-07-18T22:29:05","modified_gmt":"2012-07-18T22:29:05","slug":"aligned-sub-10-nm-block-copolymer-patterns-templated-by-post-arrays","status":"publish","type":"post","link":"https:\/\/mtlsites.mit.edu\/annual_reports\/2012\/aligned-sub-10-nm-block-copolymer-patterns-templated-by-post-arrays\/","title":{"rendered":"Aligned Sub-10-nm Block Copolymer Patterns Templated by Post Arrays"},"content":{"rendered":"

Topographic templates can be used for guiding the self-assembly of block copolymers to produce complex nanoscale patterns. In our previous work, sub-20-nm bends or meander structures were achieved based on topographic templates using 45.5\u00a0kg\/mol polystyrene polydimethylsiloxane (PS-PDMS) block copolymer [1<\/a>] <\/sup>. To template the self-assembly of 16 kg\/mol PS-b<\/em>-PDMS with a sub-10-nm periodicity, so as to scale down the resolution to sub-10-nm, the diameter of the templates must also be scaled down to the sub-10-nm range. However, the fabrication of sub-10-nm posts is challenging even with state-of-the-art lithography.<\/p>\n

In this study, we demonstrate aligned sub-10-nm block copolymer patterns, based on the understanding of the interaction between the block copolymer cylinders and posts with a range of diameters and heights. Figure 1 shows how the orientation of the block copolymer cylinders depended on the post diameter for a given spacing, L<\/em>x<\/sub> = 48 nm and L<\/em>y<\/sub> = 32 nm. The commensurate orientation of the 16 kg\/mol PS-b<\/em>-PDMS block copolymer cylinders for this array period is depicted in Figure\u00a01(b), giving a cylinder orientation of 53.1\u02da with respect to the x<\/em>-axis. The area fraction of the block copolymer oriented along the commensurate orientation was over >75% when templated by posts with a height of 16 nm and diameters from 8\u00a0nm to 12 nm. The cylinders were not aligned in a preferential orientation when templated by posts with a diameter of 6 nm. However, the cylinders were aligned parallel to the y<\/em>-axis when templated by large (diameter > 13 nm) or tall (height > 24 nm) posts.<\/p>\n

Based on the preceding result, we demonstrated every possible commensurate condition for the 18-nm period PS-b<\/em>-PDMS. As shown in Figure 2, the orientation of the block copolymer cylinders could be varied between 0o<\/sup> and 90o<\/sup> with respect to the x<\/em>-axis by using posts with a height of 19 nm and a diameter of 10 nm.<\/p>\n\n\t\t