A comparison of S-passivation of III-V (001) surfaces using (NH 4 ) 2 S x and S 2 Cl 2

D. N. Gnoth, D. Wolfframm, A. Patchett, S. Hohenecker, D. R.T. Zahn, A. Leslie, I. T. McGovern, D. A. Evans*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

30 Citations (SciVal)


Soft X-ray photoelectron spectroscopy has been applied to compare the effect of two S-passivating etchants (S 2 Cl 2 and (NH 4 ) 2 S x ) on the (001) surfaces of GaAs and InP. Detailed analysis of substrate and adsorbate core level emission peaks reveal the similar nature of S-III-V bonding in each case. Prior to in-situ annealing, the semiconductor surface is covered by an amorphous layer, and above around 400°C, a stable S-terminated surface is obtained in each case. Variations in the relative intensities of spectral features are more sensitive to process and temperature differences than to the etchants used. For S-terminated GaAs and InP surfaces, a high binding energy component is observed in the substrate Ga 3d and In 4d core level emission spectra corresponding to surface S-Ga(In) bonding. The S 2p core level spectra contain two components related to the surface and sub-surface S atoms. As-S bonding on the annealed GaAs-S surface is not present above 400°C.

Original languageEnglish
Pages (from-to)120-125
Number of pages6
JournalApplied Surface Science
Publication statusPublished - Jan 1998


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