Abstract
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 language | English |
|---|---|
| Pages (from-to) | 120-125 |
| Number of pages | 6 |
| Journal | Applied Surface Science |
| Volume | 123-124 |
| DOIs | |
| Publication status | Published - Jan 1998 |