Despite the outstanding technological importance of reactive plasmas, numerous fundamental phenomena are not yet understood. Progress in this field and the targeted development of future thin film materials and novel plasma processes require a more detailed knowledge of the interaction of reactive plasmas with the surrounding surfaces. The central theme of experimental physics II is to elucidate the underlying mechanisms of action at the boundary reactive plasma surface. The treatment of this topic leads to two fundamental questions:
- Which are the reactive species responsible for the growth of the film in the gas discharge?
- What are the heterogeneous surface reactions by which these species lead to material synthesis or surface modification?
Three main topics are dealt with:
Material synthesis in reactive plasmas
Reactive plasmas are often used to make thin films or to modify or etch surfaces. Important input variables for these processes are the particle fluxes which impinge on the surrounding surfaces and the composition of this surface, which is set in dynamic equilibrium. Mass spectrometry serves as an essential diagnostic tool since it allows a large number of species to be identified and, in the case of known cross-sections, also quantified for the detection. In addition, optical in-situ and real-time processes play a central role in the elucidation of surface processes. New developments here are the microplasms, which can be used to realize non-equilibrium processes at atmospheric pressure.
Elementary processes of plasma surface interaction
Elementary processes of the plasma surface interaction are specifically investigated in particle beam experiments. Special attention is given to the interaction with biological systems. H / O / F atoms and low-energy ions are used as quantified particle beams.
Structure formation in plasma and on surfaces
A phenomenon of reactive plasmas is their ability to form small particles in plasma or self-assembled structures on surfaces. However, control and control of these dust particles is difficult