This work explored quantitative analyses of SiGe layers, either grown on bulk Si wafers or in a confined space of different dimensions within the N28 node technology. Dynamic secondary ion mass spectrometry (SIMS) measurements were performed with a magnetic sector CAMECA IMS Wf, using low impact energy O2+ sputtering and recording the Ge containing molecular ions. It was concluded that the molecular ions protocol, called “self-focusing” SIMS, is capable of providing an accurate characterization of SiGe composition with Ge content up to 90%.