查看文章

In this paper, changes in surface Fermi-level of Si and GaAs, caused by doping and cleaning, are investigated by Auger electron spectroscopy. Based on the Auger voltage contrast, we compared the Auger transition peak energy but with higher accuracy by using a more accurate analyzer and an improved peak position determination method.

For silicon, a peak shift as large as 0.46 eV was detected when comparing a cleaned p-type and n-type wafer, which corresponds rather well with the theoretical difference in Fermi-levels. If no cleaning was applied, the peak position did not differ significantly for both wafer types, indicating Fermi-level pinning in the band gap.

For GaAs, peak shifts were detected after cleaning with HF and (NH₄)₂S-solutions in an inert atmosphere (N₂-gas). Although the (NH₄)₂S-cleaning in N₂ is very efficient in removing the oxygen from the surface, the observed Ga- and As-peak shifts are …