The formation of sacrificial oxides by UV-ozone exposure on GaAs and I
nP is a well established procedure in the preparation of clean substra
tes for MBE growth. We describe a UV-ozone treatment used to prepare G
aSb(100) substrates and report results obtained by Auger (Auger electr
on spectroscopy) which show that the quality of the so prepared substr
ates is excellent for MBE (molecular beam epitaxy).