FOR 845: Self-Organised Nanostructures by Low-Energy Ion Beam Erosion

Basic data for this project

Description

It is the research objective to win a basic understanding of the nanostructuring processes on semiconductor surfaces by low-energy ion beams with an energy up to some keV. This understanding should include all aspects of the nanostructuring by ion beams, from a description of the fundamental effects during ion bombardment by means of experimental examinations and theoretical simulations, over the study of the formation of structures on mesoscopical scale and the description through adequate theoretical models until to the exploration of selected applications. Systematic studies the topography and dynamics of the development of structure at different erosion parameters (ion energy, fluence, incident angle, target rotation) and substrate temperatures should deliver a basic understanding for the self-organisation phenomenons. On the basis of the acquired understanding it is striven to establish the method as alternative nano-structuring technology. Simultaneously, a secured database should be developed. A peculiarity of the Research Unit is the strong focus on a small class from experimentally to examined materials. For most basic experimental and theoretical studies, Si and Ge surfaces stand in the centre of the interest. Beside it some application-oriented at III-V semiconductors examinations are planned. With the applications, first proof are expected over the changed functionality of the structured surfaces or layers. For example, the moth-eye phenomena, well-known from the nature, should be generated on nanostructured quartz surfaces with the help of this self-organisation process and its suitability as anti-reflectivity layer in the VUV spectral region (broadband anti-reflectivity) should be studied. From the theoretical point of view, the explanation represents a special challenge the miscellaneous surface structures and their space-temporal evolution. In the Research Unit atomistic simulations are applied with the help of molecular-dynamic and kinetic Monte Carlo methods and, on the other hand, continuum-models for the space-temporal development. One strives for it by successive expansion, modification and consideration of further experimental details of the no-local Kuramoto-Sivashinsky equations, a largely extensive theoretical picture of the structure-forming qualities by ion beam erosion based on continuum-equations for the topography.