Reflectance anisotropy studies of the oxidation of (001) GaAs surfaces in an MOCVD reactor

The oxidation of GaAs(100) surfaces under atmospheric pressure conditions studied in real time using dynamic reflectance anisotropy spectroscopy at 2.6 and 4eV

“…From these traces it is obvious that there is an increasing rate of signal degradation with increasing flow rate/partial pressure of air. Previously we have shown that these trends are characteristic of a pseudo first-order decay behaviour [26]. Other studies of the reactivity of oxygen with GaAs have shown that the reaction tends to occur at the Ga-As bonds while As forms elemental clusters form on the surface [5][6][7][8][9][10][11] so it may be the case that the loss of the 2.6 eV signal is related to As surface migration and cluster formation rather than direct reaction of the As-As dimers with oxygen, such has been seen in other studies where the 2.6 eV signal has been made to disappear [18,20].…”

“…We found a pseudo first order decay rate for the 2.6 eV signal during oxidation under atmospheric conditions [26].…”