The subproject is mainly active as a service project and supports the other subprojects of the CRC with its expertise and machine infrastructure in the investigation of properties at surfaces and interfaces. Particular attention is paid to oxide formation at the surfaces and interfaces, possible physicochemical processes such as interdiffusion in oxide-free contact of joining partners, and the mechanisms at the surfaces during mechanical treatments under XHV-adequate conditions. The subproject also has its own research work focusing on the interaction of silane with water. In particular, research is being carried out into how dielectric barrier discharge plasmas can be used to remove the residual water content in the XHV-adequate atmosphere, which is a challenge for some applications.