By alternating acquisition and abrasion sequences, a composition profile can be traced with nanometric depth resolution. The primary ion beam, reduced to a small diameter spot, scans the surface to be imaged. The secondary optics for extraction and mass analysis are fixed. The image is reconstructed by synchronizing the secondary signal with the primary beam scan. Lateral image resolution depends on the size of the micro-beam (from 100 nm to 3 µm in diameter, depending on analysis conditions).
Other complementary techniques can be used to characterize semiconductors, such as TEM or SEM.