For detailed examination of TMR layer stacks and a special surface test (see section 4.1) a Scanning Auger Microscope (SAM) SYSTEM 660 from PHYSICAL ELECTRONICS was used. This system has an integrated SEM for the positioning on a sample and uses an integrated ion beam milling system to acquire depth profiles of samples. Using only Auger electrons with an energy between 30eV and 2000eV for the mass determination the SAM has a very high depth resolution. A comprehensive description of this system and the method can be found in [111].