Application Of Scanning Probe Microscopy On The Research Of Porous Material Preparation, Nanolithography And High Density Optical Storage

Scanning probe microscopy (SPM) provides measurement of surface morphology on atomic scale. It has been widely applied to surface science, nanomedicine, nanomeasurement, life science and so on. Further, SPM has also been applied successfully to nanofabri cation and nanolithography. This paper is divided into five chapters:1. The principle and working modes of various SPMs have been explained and its applications to nanolithography and near-field optical storage have been introduced.2. AFM images are often subject to some artifacts arise from scanner nonlinearities, parameters of feedback loop and the interaction between probe and sample. The methods of identifying and eliminating the artifacts have been represented.3. A new method of preparing porous monolayer film by immersing stearic acid Langmuir-Blodgett monolayer into salt solution has been proposed. The formation mechanism of the porous structure has been analyzed. The morphology images of porous films prepared with different experiment parameters (immersion time, concentration of the salt solution, cationic valence in salt solution, surface pressure of the SA LB film) are characterized by atomic force microscope (AFM). The influence factors on diameter and coverage percentage of the pores on porous film have been systematically studied. With lower concentration of the salt solution, the solute cannot crystallize on mica surface, which avoids the step of removing template materials in all template methods.4. Based on the surface plasmon polariton (SPP) effects, utilizing near-field optical microscope (SNOM) tips, two recording methods of near-field optical storage have been proposed (back and lateral illumination). As the light source requires an external trigger signal to work, we have designed a nanosecond scale single trigger signal generator based on the xilinx9572chip. The GaAs pyramidal tip produced by liquid phase epitaxial method has been successfully integrated with AFM cantilever of contact mode for back illumination, which achieves the nano-scale control of GaAs tip and phase-change material. In the method of lateral illumination, the influences of incident angle and the focal spot size on enhancement factor have been researched with finite-difference time domain (FDTD) method. Meanwhile, the urgent issues in the experiment have been discussed. 5. Considering the poor feedback of crew-cut probe, the bowtie aperture surrounded by bull’s eye structure has been integrated on thhree-dimensional SNOM tip model. This model has been investigated using FDTD method. Based on the common working wavelength of photolithography (365nm), the period of the bull’s eye structure for SPP resonant effect are achieved with corresponding equations. The enhancement mechanism of the model has been represented according to the numerical simulation results. Meanwhile, the influences of structure parameters on enhancement factor have been analyzed and optimized. Further, we proposed a new improved method.