Fabrication of none-ridge nanogrooves with large-radius probe on PMMA thin-film using AFM tip-based dynamic plowing lithography approach

Abstract

In this study, the AFM tip-based dynamic plowing lithography (DPL) method is utilized to conduct nanoscratching tests on the poly(methyl methacrylate) (PMMA) thin-film surface. Aim to fabricate none-ridge nanogrooves, a relatively large-radius probe in wear state is employed for the whole scratching operations. Due to large contact area between the tip and the sample surface, the energy dissipation fails to break the polymer chains. The extrusion force is contributed to the formation of the none-ridge nanogrooves in the machined areas. Effects of the scratching parameters, including the drive amplitude and the scratching velocity, on the machined depth are discussed in detail. Results show that the machined depth increases linearly with the drive amplitude going up owing to more energy dissipation accumulated. Moreover, the logarithmical decrease in machined depth with respect to the scratching velocity is thought to be induced by enlarging the spacing distance between two press operations. A nanochannel can be achieved by controlling the distance between two adjacent scratching grooves which is generally called ‘feed’. The overlapping of the two adjacent scratching grooves can result in an increase of the machined depth. Finally, two geometries of controllable three-dimensional (3D) nanodot arrays are achieved by a two-step scratching approach successfully.