Nanofabrication of high aspect ratio structures using an evaporated resist containing metal

作者：Con Celal^*; Zhang Jian; Cui Bo

来源：Nanotechnology, 2014, 25(17): 175301.

DOI：10.1088/0957-4484/25/17/175301

• electron beam lithography
• electron beam resist
• polystyrene
• evaporated resist
• high aspect ratio
• plasma etching

Organic electron beam resists are typically not resistant to the plasma etching employed to transfer the pattern into the underlying layer. Here, the authors present the incorporation of a metal hard mask material into negative resist polystyrene by co-evaporation of the polystyrene and the metal onto a substrate. With a volume ratio of 1: 15 between Cr and polystyrene, this nanocomposite resist showed an etching selectivity to silicon one order higher than pure polystyrene resist. Silicon structures of 100 nm width and 3 : 5 mu m height (aspect ratio 1: 35) were obtained using a non-switching deep silicon etching recipe with SF6 and C4F8 gas. Moreover, unlike the common spin coating method, evaporated nanocomposite resist can be coated onto irregular and non-flat surfaces such as optical fibers and AFM cantilevers. As a proof of concept, we fabricated high aspect ratio structures on top of an AFM cantilever. Nanofabrication on non-flat surfaces may find applications in the fields of (AFM) tip enhanced Raman spectroscopy for chemical analysis and lab-on-fiber technology.

• 出版日期2014-5-2