Research On The Numerical Simulation Of Plasma-based, Template-assisted Nanofabrication Nanodot Arrays

It is an effective technique to fabricate nano-dot arrays using plasma based template-assisted nanofabrication technique. Nowdays, the main problem we faced is the poor penetration of species deep into the nanoporous in the template and nanoporous clogging caused by uncontrollable precipitation of species. This problem is extreamly serious during the deposition of dielectric materials. Because the positive charges will accumulated on the template surface and reduce the potential on the surface.In this paper a three-dimensional microscopic topography of ion flux distribution over the outer and inner surfaces of the nanoporous template is obtained by a multi-scale Monte-Carlo numerical simulation. We investigated the possibility of controllable plasma based nano-material fabrication using nano-scale template.1. This thesis reports a Monte-Carlo simulation of transport and deposition of metallic ions onto the three-dimensional nanostructured template/substrate system. The investigation on three-dimensional microscopic topography of ion flux distributions over the surfaces of the nanoporous template has enabled us to optimize the plasma process conditions that make it possible to grow cylindrical nanodots within the nanoporous. Moreover, nanodot shapes can also be predicted from this simulation.2. We presented a numerical simulation work, in order to implement the templated i-PVD of dieceltric nanodots metrials. During the deposition of dielectric material, electric charge accumulated on dielectric surfaces exposed to plasmas and ion beams distorts ion/cluster trajectories and reduces the process throughput and precision. Our result demonstrated the advantages of using a pulsed substrate bias with properly adjusted pulse durations and voltages to sovle the problem. We investigate the distribution of ions with different bias voltage, pulse duration and duty cycle. And explore the way to ehance the deposition rate of the dielectric material. This technique can maximize ion penetration into the pores and precisely control their deposition onto the inner nanopore surfaces. Under the optimized conditions, the ion flux is distributed uniformly over the lateral nanopore surfaces and, more importantly, is effectively focused near the center of the pore bottom opening. The results of this work are applicable to various processes involving pores dielectric nanomaterials and dense nanoarrays.3. In the first and second section we studied the distribution and motion of ions. The result can show the influence of the parameters to the deposition during the process. However, the neutral species is the dominant factor in the low temperature plasma and it is necessary to investgate the deposition process with the influence of neutral species. The result shows that the plasma density and electron temperature are important during the depositon. Both the distribution of species on the lateral surface of the pores and the relative deposition rate are affected greatly by the electron temperature. The bias voltage only can influence the deposition at high plasma density. The plasma density can affect the relative deposition rate and the amount of species on the lateral surface, but shows no influence to the distribution of species on the lateral surface of the pores. The results also indicate that with higher dimeter nanoporous, one can get higher depositon rate.The result indicates people should choose proper parameter based on the ionization rate and the size of the nanoporous.