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mbeam, focused ion beam, nanoimprinting and nanosphere lithogra-phy, consist of several steps and require pre-defined patterns in a nanoscale [18–21]; moreover, it is hard to realise large-area fabri-cation for some of the above processes. Other maskless processes, such as the metal-catalysed chemical etching process [22, 23], are hard to control and are not compatible with the CMOS processes. The reactive ion etching (RIE) process [24–26] is also a single-step method without masks to make black silicon surfaces, but it cannot get high-aspect-ratio structure, which is important for high-quality applications, for example, the micro/nano dual-scale (MNDS) structures consisting of accurately defined microstructures have been reported [27–30] for hydrophobic devices. Recently, femtosecond laser [31] also has been reported as an important maskless process to form a black silicon surface. Differing from other fabrication techniques, we previousl