A Research Of Nanofabrication By Plasma Technology Using Template

This thesis theoretically investigates how parameters, in experiment by plasma technologies using different nanostructural templates to fabricate metallic or dielectric nanostructures, affect the final results. The details are listed as follows:(1) This thesis reports the numerical simulation of plasma-based, porous template-assisted nanofabrication of Au nanodot arrays on highly-doped silicon from low-temperature plasma of typical plasma density and electron temperature. Three-dimensional microscopic topography of ion flux distribution over the outer and inner surfaces of the nanoporous template is obtained via numerical simulation of Au ion trajectories in the plasma sheath, in the close proximity of, and inside the nanopores. It is shown that by manipulating the electron temperature, the cross-sheath potential drop, and additionally altering the structure of the nanoporous template one can control the ion fluxes within the nanopores and eventually maximize the ion deposition onto the top surface of the developing crystalline Au nanodots and minimize amorphous deposits on the sidewalls that clutter and may eventually close the nanopores thus disrupting the nanorod growth process.(2) This thesis presented a numerical simulation of depositing dielectric material using an insulating porous template. A maxwellian distribution has been used to calculate the original ion velocity when the ion leaves the plasma and enters the sheath. It is found electron temperature and nanopore structure can change the ion deposition rate effectively. The result of our paper indicates that templated i–PVD of dielectric nanodot is quite different from templated i-PVD of metallic nanodot, and people should try some new ways by plasma to fabricate dielectric nanodot using porous template to make the effect from the electrical field and the substrate bias stronger.(3) This thesis studies the results of numerical simulations of nanometer-precision distributions of microscopic ion fluxes in ion-assisted etching of nanoscale features on the surfaces of dielectric materials using a self-assembled monolayer of spherical nanoparticles as a mask. It is shown that the ion fluxes to the substrate and nanosphere surfaces can be effectively controlled by the nanosphere sizes, the plasma parameters, and the external bias applied to the substrate. By proper adjustment of these parameters, the ion flux can be focused onto the areas uncovered by the nanospheres. Under certain conditions, the ion flux distributions feature sophisticated hexagonal patterns, which may lead to very different nanofeature etching profiles.From the results in this thesis work, it can be seen that numerical simulation can be used to explore how different experiment parameters affect the ion trajectories and how they influences the shape of final nanostructures. Therefore, through detailed study of plasma parameters and the template structure, it is possible to effectively control the nanofabrication of nanomaterials by plasma technologies.