Fraunhofer Institute for Interfacial Engineering and Biotechnology IGBFor many technical products that we deal with in our daily lives, thin layers are applied during production and the surfaces are adapted to the respective requirement profile. Some techniques, such as painting or galvanic metal deposition, are familiar to everyone. Vapor deposition with metals is also frequently used, with aluminium coating being the most common.
Development of efficient plasma processes by optimizing the process control
Fields of application
Another important technique is plasma-assisted processes. Plasma technology is considered a key technology and makes important contributions in a wide range of application fields - from plastics and metal processing, packaging, automotive, electronics, optics and energy technology to medical technology, biotechnology and diagnostics. Plasma processes provide new and better solutions for many materials-related problems. Applications in the field of nanotechnology are also becoming increasingly important.
Effect of plasmas
High-energy and reactive particles from the plasma gas phase bombard all materials in contact with them. They can, depending on the process control,
- remove the surface,
- create chemical functions on the surface or
- Separate layers.
Ablation, functionalization and deposition take place simultaneously as elementary processes in every plasma treatment. Thus plasma processes can be used for
Which of the processes determines the net result of the treatment - whether etching or coating is ultimately preferred - depends on various parameters in process control. For each task, we determine the optimum parameters for the desired change in surface properties.
Optimal process control for surfaces as required
The Department of Interfacial Engineering and Materials Science at Fraunhofer IGB has many years of experience in the development and optimization of plasma processes for a wide range of tasks. We first control the processes within a plasma using gas flow, pressure, excitation frequency and power.
The adjustment of these plasma parameters influences the density and energy of the charged particles, the density of chemical radicals and electronically excited particles as well as the radiation generated by the plasma - all of which together determine the physical-chemical effect of the plasma. It must be taken into account that the above-mentioned effects can differ spatially within a plasma, especially in the vicinity of surfaces.
Another major difficulty is that the processes within the plasma cannot usually be controlled independently of each other, and the relative dependencies are often not easy to identify. In order to gain insight into these interdependencies and to optimize the plasma process, we at Fraunhofer IGB use different methods of plasma diagnostics.
Plasma diagnostics and surface characterization - process and result control during and after treatment
During and after the treatment, the process conditions are controlled and, if necessary, supporting plasma diagnostic methods are used.
The product surfaces exposed to the plasma are examined after the treatment with different methods depending on the requirements. For this purpose we have extensive surface analytical facilities at our disposal. In this way we try to find optimized process parameters and establish controlled and reproducible processes.