BACKSCATTERING LIMITATIONS TO SPATIAL-RESOLUTION IN THE AUGER MICROPROBE

As Auger instrumentation for submicron analysis has improved with the introduction of field emission sources and multichannel detectors, the range of practical operating magnification has been pushed above 20000 x . This implies Auger analysis with spatial resolution comparable to the range of the primary electrons in the solid and care must be taken in interpreting results. Backscattering effects can limit spatial resolution in Auger electron spectroscopy, especially in particle analysis. An example of Auger analysis of a 0.7 mum cube of TiN on steel at 3 and 20 kV is shown, together with Monte Carlo simulations of electron scattering (SEEL). Correlation of the model and experimental results is in good agreement. In this case, lower primary beam voltage reduces scattering limitations to spatial resolution. The optimum beam voltage for maximizing spatial resolution depends on the sample, on the Auger transition being measured, and on the instrument.