Nanostructures have attracted more and more attention due to the potential applications in many fields such as the light catalysis, biological sensing, electromagnetism and super hydrophobic materials. At present, the advanced nanofabrication technologies include electron beam lithography, focused ion beam direct writing and probe direct writing technology. These techniques can fabricate high-resolution nanostructures, but low efficiency and high cost of mass production are still big challenges.
Hu Song group proposed a new method for fabricating nanobowl array from Institute of Optics and Electronics, Chinese Academy of Sciences. This method combines polystyrenes spheres (PSs) self-assembly, nanoimprint lithography (NIL), and lift-off process. The fabrication approach is shown in Figure 1. A self-assembly monolayer of PSs on the quartz wafer is used as the nanoimprint mold. After separating the mold, the residual PSs onto thenanoimprint resist can be lifted off in the hydrofluoric acid solution and the nanobowl array is achieved. The size of the nanobowl can be modulated by the imprinting pressure and resist thickness. The experiment results are shown in Figure 2. This new fabrication method could be used to make different size of nanobowl arrays, which has great potential to serve as a reaction container, catalyst and surface enhanced Raman scatteringsubstrate.
The relevant results are published in OPTIK. 
by Zhang Man
