Experimental Research Of Machining Nano Structrues On Polymer Surface Based On AFM Tapping Mode

Atomic force microscopy (AFM) is widely used as a new way of processing,because of its unique integration of processing and detecting, high-precision,high-resolution features. According to processing methods, AFM processing can bedivided into contact mode processing and tapping mode processing, compared tocontact mode, tapping mode processing influenced by processing direction little, andapplied to a variety of polymer surface processing. This thesis studies the AFMsingle crystal silicon probe processing on polycarbonate (PC) and polymethylmethacrylate (PMMA) surface under tapping mode. Undertake the following work:First, on the basis of the existing linear damping vibration model, simulatingthe relationships between probe and sample surface with Matlab, to get the effect ofdrive voltage, tip radius, drive frequency and the coefficient of elasticity of the probecantilever on the tip indentation depth, the maximum force between the probe andthe sample and the maximum compressive stress. Getting the conditions of formingplastic deformation on polymer surface, and find the parameters that can easilycontrol the depth of processing. Guidance to subsequent processing experiments.Secondly, when AFM process a rectangular area of PC surface under tappingmode, will form rules protruding, and the reason is unclear. During the experiment,we found that, as AFM processing a line under tapping mode, the formation of thebulge volume is greater than the crater volume, so guess the reason of raised areawhen processing a rectangular area is a number of segments superimposed, in orderto verify this speculation, by combination of simulation and experiment to analysisthe raised structure under different step, and the reason of raised structure.Finally, according to processing and experimental needs, write requiredparticular trajectory program with AFM systems. On this basis, study the effects ofprocessing speed, drive amplitude, and step on processing polymer, and analyze itscauses. Found that different exciting voltage on the tip caused different form ofcutting on polymer surface. As the exciting voltage is small, the material depositedon the groove on both sides of groove, as the exciting voltage is big, the tip formedcutting on the polymer surface, chip stacking in the end of the processing path.Finally processing on a variety of polymer surface to get nanometer-sized fraphics.