Fabrication of Nanoscale Pits with High Throughput on Polymer Thin Film Using AFM Tip-Based Dynamic Plowing Lithography

Abstract

We show that an atomic force microscope (AFM) tip-based dynamic plowing lithography (DPL) approach can be used to fabricate nanoscale pits with high throughput. The method relies on scratching with a relatively large speed over a sample surface in tapping mode, which is responsible for the separation distance of adjacent pits. Scratching tests are carried out on a poly(methyl methacrylate) (PMMA) thin film using a diamond-like carbon coating tip. Results show that 100 μm/s is the critical value of the scratching speed. When the scratching speed is greater than 100 μm/s, pit structures can be generated. In contrast, nanogrooves can be formed with speeds less than the critical value. Because of the difficulty of breaking the molecular chain of glass-state polymer with an applied high-frequency load and low-energy dissipation in one interaction of the tip and the sample, one pit requires 65–80 penetrations to be achieved. Subsequently, the forming process of the pit is analyzed in detail, including three phases: elastic deformation, plastic deformation, and climbing over the pile-up. In particular, 4800–5800 pits can be obtained in 1 s using this proposed method. Both experiments and theoretical analysis are presented that fully determine the potential of this proposed method to fabricate pits efficiently.

Tip-Based Nanomachining on Thin Films: A Mini Review

“…To date, nanodots/pits, nanogrooves/lines, and even three-dimensional (3D) complex structures have been achieved on these films by using the TBN method. Various types of nanomachining methods based on tips involving static scratch [33][34][35], DPL [9,13,14,36,37], and vibration-assisted approach [22,[38][39][40][41][42][43][44][45][46], especially the ultrasonic vibration-assisted (UV-assisted) method, have been used to machine nanopatterns on polymer films (Table 1). Heated tips have been found to offer important advantages in machining polymer film materials.…”

“…On the surface of polymer films, nanodot arrays can be fabricated via tip nanoindentation directly or through the overlap of two machined nanogrooves by a single scratch performed twice in different directions [13,36]; a third scratch may be employed to improve density [13]. Nanopits have been obtained using a tip that is pressed into a sample, similar to nanoindentation [1] or DPL based on tapping [9,37]. Some scholars have found that heated tips can modify polymer surfaces by changing their properties by heating.…”

Scratch on Polymer Materials Using AFM Tip-Based Approach: A Review

“…Many scholars have obtained nanopits using the TBN method and studied the influence of scratching parameters on achieved nanopits. He et al [82] used the DPL method, which is based on the tapping mode of AFM to scratch nanopits on PMMA thin films with high efficiency. In this study, a critical scratching velocity was observed to form nanopit.…”

“…Surface morphology images of nano-pit arrays at a scanning speed of 400 μm/s in the scan size of 5 μm measured by AFM: ( a ) 2D images, ( b ) zoom-in image of figure ( a ) at a dimension of 2 μm, ( c ) 3D image of ( b ), ( d ) cross-section of ( b ) [82]. …”

Features of the study of binder state near the filler particles in elastomeric composites using an atomic-force microscope

“…Effective management of the processes and phenomena occurring at these scales makes it possible to purposefully create materials with fundamentally new characteristics unattainable with the use of traditional technologies. Nowadays atomic force microscopy (AFM) is one of the most promising tools for such studies [1][2][3][4][5]. Its main advantage over conventional electron microscopy is that the AFM allows us to obtain information not only about the topology of the internal structure of the material, but also about its local physical properties.…”