Elemental and chemical microanalysis of silicon surfaces by reflected electron energy loss microscopy and scanning Auger microscopy

While the chemical sensitivity of SAM is far superior to that of REELM, the latter technique allows accurate chemical state analysis of different silicon species.

Reflected electron energy loss microscopy (REELM) and scanning Auger microscopy (SAM) are used to highlight lateral and vertical chemical changes at the interface between atomically-clean silicon and oxidized/contaminated silicon surfaces. Lateral chemical contrast is achieved in both SAM and REELM imaging, provided that an appropriate primary electron energy is used in the latter. While SAM is limited by the fixed information depth provided by Auger signals, REELM offers a wide choice of surface sensitivities which permit non-destructive depth-profiling.