W. Passenberg et W. Schlaak, SURFACE PREPARATION FOR MOLECULAR-BEAM EPITAXY-REGROWTH ON METALORGANIC VAPOR-PHASE EPITAXY-GROWN INP AND INGAASP LAYERS, Journal of crystal growth, 173(3-4), 1997, pp. 266-270
MBE regrowth on MOVPE grown InP and InGaAsP (1.06 mu m) layers was fou
nd to demand appropriate surface treatment for not sacrificing epitaxi
al growth performance. Wet chemical etching using a sulphuric acid bas
ed solution as well as surface oxidation using UV light/ozone exposure
were found to give very satisfactory and basically equivalent results
. Particularly with the quaternary material, both methods prove to be
destructive in that a non-neglible amount of material is removed from
the surface. The removed thickness tends, however, to be smaller with
the UV/ozone based process, an advantage, which becomes especially app
arent in the presence of lower band gap InGaAs(P) layers which are str
ongly attacked by the sulphuric acid etchant.