Iodine etching of the GaAs(1̄1̄1̄)As surface studied by LEED,AES, and mass spectroscopy

The iodine interaction with the GaAs(1̄1̄1̄)As surface prepared by molecular beam epitaxy has been studied by LEED, LEED intensity measurements, Auger electron spectroscopy (AES) and computer controlled mass spectroscopic study of the whole desorption spectrum. It is shown that an iodine beam hitting the GaAs(1̄1̄1̄)As face at 300 K under UHV conditions etches the surface continuously. After this etching there remains an adsorbate of GaI_x where x is a number between 0 and 3. By thermal desorption of this GaI_x adsorbate an As stabilized GaAs(1̄1̄1̄)As surface showing a (2 × 2) structure can be prepared, which up to the present could be done only by molecular beam epitaxy.