Analysis of Multilayers (Layer Systems)
From Optics to Semiconductors

Metallic multilayer systems are used in many different ways on many substrates. They are an integral part of many optical components (e.g. lenses, dielectric or dichroic mirrors, interference filters ...). Multilayer systems are also used as heat protection layers on glass, to improve electrical contacts on metals, as complex layer systems in semiconductors and to enhance the look of plastics. In some cases, functionalized surfaces play a role. The use of surface analysis techniques can be very useful both in the development of new multilayer coating systems and in quality assurance.

A variety of analytical techniques are available in our laboratory and, depending on the analytical question or the respective defect, we have the experience to select the best technique or combination of techniques to answer the specific question of interest. Both ToF-SIMS and XPS can be used to characterize multilayer systems. A ToF-SIMS depth profile analysis enables the layer structure and layer composition to be characterized very precisely. Traces of impurities in the layer system or at interfaces can also be detected and identified with high sensitivity. Layer sequences and layer thicknesses can be analyzed. XPS is particularly useful when the chemical bonding of the elements in the layers or the precise quantification in the individual layers of the multilayer layer system is of interest. Other techniques, such as electron microscopy (REM-EDX), are also available.

The following example from our laboratory shows a case in the field of damage analysis and quality assurance. The strengths of the ToF-SIMS depth profile analysis on optical glasses become clear here.